Gen, are you getting the impression that girls react negatively to you?
You are a giant ranga (that's what we call redheads here). And girls are usually very intuitive, most will pick up very quickly that you are a bit different. I've seen your photos, you are not ugly or unattractive, it's not that.
If you have anxiety issues about your lack of intimate experience, how girls perceive you, your attractiveness, your body language, all of those things, then that is going to impact on how you relate to people and further compound whatever issues you are having.
I will now go into "relationship coach" mode. If you don't want me as your relationship coach, please feel free to tell me to fuck off.
Don't worry about first impressions. They don't matter, and you will probably misread whatever first reactions you get from people anyway. I know it's difficult when you meet someone for the first time and they give you a dirty look or they turn their nose up. That can just be defensive behaviour.
In 2001 I was sitting outside at a pub in Europe with a bunch of other expats, some were IT workers like myself and some were English teachers. Now a few years earlier I had made a conscious decision to be less self conscious and to actually make an effort to talk to people regardless of how I felt they might react. A girl joined the table with a few other people, she was attractive and a lot younger than I was and she was from New York and she was LOUD. She said something interesting and I asked her a question. She just turned around and looked straight at me and said (loudly): "you know that I'm never going to sleep with you, right?". I just told her that I knew that she was an attractive young woman but the world is full of attractive young women who won't ever sleep with me, and I'd rather sleep with someone closer to my own age anyway. Anyway, to cut a long story short, despite getting off to a very weird start that I could have taken in a negative way (but chose not to), we became good friends over the next few months and that progressed to a romantic/intimate relationship that only ended (eventually) due to the tyranny of distance.
And I'm not trying to brag about my shagging exploits or anything like that (maybe a bit). I'm just saying that you need to STOP stressing about the small stuff. And stop stressing about the big stuff. Are you good at socialising with girls? If not, then that is a good place to start. Get used to just talking to people, asking leading questions, being a good listener, not oversharing.
Do you know why relationships just kind of happen to most people? Because social skills come more naturally to them. They meet and interact with people and they make connections and things tend to progress towards relationships and intimacy from there.
This is also why relationship advice from most people is so useless. Because they are speaking from a position of having those basic innate social skills and taking them for granted.
One of the best things you can do is to just learn to be friendly to people who don't like you and who act like they don't want to interact with you. Someone ignores you? Just be friendly and ask them how their day is going. Someone snaps at you, make a point of saying something friendly to them a bit later. Conscious efforts to do these things is required.
