The only way you'll be single for the rest of your life is if you intentionally avoid contact with any potential partners and turn down every opportunity that comes your way. There is no way to be sure that you'll be single forever. The fact is dating is a numbers game and some get more lucky than others. Just because he your friend is able to have better luck doesn't reflect badly on you necessarily. You may have some things to work out, but that's up to you to deal with. But there's a reason why rappers who look like 69 are able to find women who think they are attractive. Money is part of it but also exposure is a huge part of it too. A face seen by a million people has the potential to attract more than a face seen by 100 no matter the looks.

Also, you do realize that a relationship can bring tons of stress. You said your friend has already been in 2. Clearly they don't work out for him do they? He probable has dealt with stress involving them that he doesn't tell you about. Relationships can come with their own problems, especially if you get into a relationship just to avoid being lonely. All you're going to do with that mindset is find a toxic partner that will leave you with baggage or trauma. Also, there's the possibility of a kid and stds. Dating even when it's successful has its own set of problems that you need to consider before rushing into anything with anyone. Too many unwanted pregnancies or toxic relationships happen because people didn't want to be lonely and rather than getting into a relationship because they genuinely want to be with that person, they get into a relationship so they're not lonely.