real advice would be very muc appreciated, my life is an actual mess

I am 25 now. I am short, balding and have a small dick. it gets even worse, no one understand what I am going through. if I would tell anyone about it, people would laugh at me, they could not take me seriously. if you even suggest that your problems are due to what you have been given at the beginning of your life you wont be taken seriously. it‘s not only the dating aspect, even though dating as a person in my position is an absolute zero game. noe one wamts someone who has been dealt with the wordt in every physical aspect that actually matters. and not only that, I am also stupid. I always wanted to go to college and study mathematics but my cognitive abilities do not match up with what I am interested in. I have done numerous of cognitive ability tests, credible ones conducted by a psychologist. I never scored above 95, I am even below average intelligence, in something I thought I could at least excell. the math degree is off the table obviously, I have tried it, I have failed, I have worked harder than most people but I still could not make it. when all your friends end up with the life you have always wanted, when they achieve everything you wanted to do with minimal effort it gets enormously frustrating. more than anything one could ever imagine. intelligence(what I am referring to is really ones raw cognitive abilities) matters and looks matter too, more than most people would ever realize, you only get exposed to that fact once you actually are in exactly that position. it‘s not that I am not a van neuman or hilbert, it‘s that I am honestly not very capable cognitively. it‘s frustrating as hell and no one takes it seriously. my lives is going downhill at this point, nothing actually works out the way I expect it to be, not in any branch. people told me as long as I work hard for it I can get what I want even though, this is painfully inaccurate. there are things some people can never achieve. my life is a mess and I have no idea what to do with it, how to handle it. I am also horribly alone, the last time I attempted to date someone was 7 years ago, since that all I got was rejections. people will tell you it‘s because of your „personality“ when in fact rejections come from people explicitly naming your height as the reason why they are not interested in you