'Align' yourself rightly and properly. You are not aligned so you have difficulty fulfilling desires and ambitions. When we are aligned, we don't have to wait for things to happen, nor struggle to get what we want. We attract what we are attracted to, and it attracts us, by our inner alignment. 'This' and 'that', 'here' and 'there', 'now' and 'then', do not matter when you are aligned, because the inner decision to 'become', sets the conditions to fall into place for it to happen. There is nothing magical about it at all, just how things work.
Seemingly capable people tend to fall on hardship when they impose limitations on the world, self and others, that keep them from realizing their goals fulfilled. Your problem is not superficial at all. Guys don't place as much importance on that, and will try to hook up with almost anything (sad to say). I suspect that guys have an intuitive sense (which most of us are unaware of), that keep us away from what we're attracted, "beneath the surface," just as I believe women have theirs.
In regards to sex, you could be sending a inner signal that puts guys off, when they are reading your outward appearance, which tells them "keep away". I know a lot of guys who have this problem, nearly being everything women typically ask for in a "good guy", but cannot get the time of day from the opposite sex. I think it is natures way of sparing us the disaster that will befall us for having the wrong idea about something that actually distorts reality. We become like "sparrows" thinking ourselves to be "hawks", and wonder why hawks wont play with us.
If I may, just to give you an example of how unaware we are of the signals we give off, I'll use your own words to demonstrate. You want to 'loose your virginity, but can't find a decent guy,' you have no perceived physical flaws, timid in initiating contact, and ready to have sex in a mutually non-committal relationship. That is a difficult set of conditions to contend with in getting what you want. What you 'think' you want, and what you think the problem is has no reality outside of your mind.
In your case, without the conditions, you would likely not be a virgin. But that isn't really what you want, you want a "decent" guy to loose your virginity to, so just loosing your virginity is not an option for you, at the moment. Most people do not have trouble finding a willing partner to have sex with because the person's character isn't the top priority. You've narrowed the field by inserting "decent guy" to the equation, and on top of that you are too shy to approach one, even if you have a inkling that he's ideal.
You are also "competing" in a field of like minded people looking for the same thing. If decent guys were easy to come by, what women would have guy problems? To make you matters even more difficult to surmount, the "decent guy" must be someone who is sufficient to meet your demands and is casual in their attitude towards the relationship. That is the "kicker!" Imagine, all the guys that pass through your observation each day, then think of how many are worthy of the title "decent", then take that percentage and imagine how many of them fit the profile of someone you're looking for.
Take into consideration that we're prone to blowing figures out of proportion in our minds, especially when it comes to things we want or are interested in. Whatever figure you come up with reduce it by 75% it is probably close to the actual number, and you'll get a sense of what you're up against, then you can begin to address your real problem. How many times have you observed with yourself and others, when what is wanted if finally obtained, only to have "buyers remorse". "Be careful what you wish for, or you just might get it."
What sort of "decent guy" only accepts part of who and what your are, and in turns says, the rest of you isn't that important. That is what your asking for. Maybe that is what you want. But in all of your experience with relationships, what makes you think you can recognize a "decent guy" when one is presented to you, or that it will be the experience you expect? I am sure there are some, who would fit the description of what you're looking for, but they are very few and far between, even compared to just "regular" decent guys.
As a guy, who appreciate guys who treat women with higher standards than they would have for themselves, I believe you are robbing yourself, and whom ever it may be you end up with, as well as the people you're meant to be with. Actual "decent" guys probably pick up on this and are repelled in another direction, while all the remaining "willing" guys, of all character and personality traits, are just filtered out of the equation, which puts you in a bubble of isolation.
There is nothing really wrong or bad about what you, or what you want, it is just your inexperienced perception and expectations you project externally. I think that is what is coming off and turning viable candidates away from you. Of course, we'd all would like to have outcome playout in the exact way we imagine them, but that is not always realistic. When we insist that our fantasies are realities we tend to alienate those around us, and end up alone, even when have people who are eager and interested in getting to know you.
You're from the UK, and I refuse to believe that you cannot "find" a decent guy to loose your virginity to. I can definitely believe that you cannot find a decent guy to have a casual relationship with, because decent guys are not typically ALIGNED with that ambition. You are setting yourself up for failure and disappointment, even if you do get what it is you perceive you want. You may not know it, because most people wont tell you, but you are every jerk and @$$hole's "dream girl", just right for taking advantage of.
To you, your ambitions may seem simple and innocent, but to many guys, who've mastered how to "appear" as a "decent guy", you are an opportunity to seek out and exploit. Too many unsuspecting women fall for the same ruse, and tend to conclude that "all guys are that way," and the real good guys out there continue to "finish last." It is all too easy to give into weakness and lower yourself an object made for "giving and receiving" physical pleasures and delights. Then you become a willing participant in contributing to the failed state of relationships most people don't seem to have figured out.
Adjust and modify what it is you're really seeking, and align yourself with it. 'Alignment' is an attitude that doesn't settle for anything less, real or imagined, than what one has already set their sights on. Being a "housewife" and a "dope dealer", can be a glamorized fantasy you might be able to act out, but they are not exactly in alignment with each other to bring successful results in both respects. 'Involvement' is about 'self-involvement', in which everyone else and their interest are background props. Alignment is interested the total surroundings in which you find your own satisfaction.
Hope this helps, sorry it was so long. Good luck in all your pursuits!