No, I do not think there is such a thing as being too attractive. And, from what you have posted, it doesn't sound like your appearance is the problem. Rather, it seems like the reason you are not getting approached more is because of your insecurity and the energy you're giving off. In your post, you said that girls who are "less attractive" than you are getting approached more than you. I think the way you see the problem is actually part of the problem. First of all, what each of us finds attractive is different. These women may be less attractive by your standards, but more attractive by others' standards. Some people are very attracted to bleached hair, heavy make-up, certain clothes, etc-- but others find that unattractive or overdone and much prefer natural beauty. Second, you're assessment that these women are "less attractive" only takes into account their physical appearance. They may have other attractive qualities about them like confidence, intelligence, a sense of humor, a positive attitude, inviting body language, good social skills, etc. You would be surprised by how much attraction is based on things like smiling, laughing, having positive energy, being warm and friendly, etc. Those things go a long way. If you are not exuding those qualities, others may perceive you to be far less attractive than what you perceive yourself to be, based solely on your physical appearance. I think sociability is also a factor here. You said that you feel you are a "loner" and often go out to places alone. This can also send off a negative message. What often makes people stand out and appear attractive is the way they are engage with other people (laughing, talking, having fun, being "the life of the party"). If other women are at the bar in groups, having fun, etc. they are going to look much more desirable than someone sitting quietly by herself. Being out alone-- when other people are in groups-- can also cause people to wonder if perhaps you don't get along well with others or if you aren't very sociable. Another issue is that men tend to avoid women who don't get along well with other women. It's a big red flag. It suggests issues of insecurity, conceit, jealousy, etc. Finally, since you describe yourself as a "loner," I would suggest that your issue isn't specific to romantic relationships. It sounds like maybe you're giving off the wrong energy in general, which is impacting your ability to develop friendships and other kinds of relationships. Because of this, simply toning down your make-up or hair isn't going to have any effect. The issue isn't what you look like. It sounds like your insecurity is causing you to give off the wrong impression (maybe to compensate for being insecure you act overly secure to the point of appearing conceited, or maybe you act nervous, or maybe you seem unfriendly). Of course, I don't know if any of these are true since I don't know you IRL, but I would guess that these are more likely the issue than anything about your physical appearance.

Speaking from personal experience, I can say that the amount I am approached tends to have less to do with my hair, clothes, make-up and more to do with the way I carry myself, how friendly I am, and the kind of energy I am putting out. I'm also blonde (naturally) and I have a fairly large chest (also naturally) and I like to dress nice when I go out. But I don't lead with my appearance. I don't look around and compare myself to other women. I don't scan the bar for who might be looking at me. I just go with my friends, put my attention on them, and people frequently approach me/us because we look like we're having a good time. Yes, being physically attractive is part of it, but it's also about looking friendly, fun, confident and sociable. If you put out positive energy, you tend to get it returned.