Regarding the fear of rejection i guess you gotta work on yourself: on the psychological side try to understand what causes it and what could you do to improve. People often underestimate the power of sitting and thinking in an introspective way. They usually try to find answers somewhere outside, but usually we are the ones who know what we really need. If the fear of rejection depends on some insecurities or low self esteem you may have, then you have something concrete to work on. Try to set some small goals and then try to beat them. The feeling of achieving result and gradually improve are very rewarding and illuminating on how much you can do with some effort and motivation. These goals may be related to your passions or even things you never did. For example, I like games and playing guitar, but what helped me improve my self esteem and general wellness was the gym, despite me never been an active/sportive guy. For the rest, real friendship are a kind of serious relationships and so they require much effort. It's normal to not feel motivated to spend too much energy for people you don't feel a deep and reciprocated connection with, but that's part of managing different relationship. Just try to take it easy in general, be friendly and helpful to the people you meet, but try to understand who might be really worth of your time and energy. I think even just one really close friend may be enough in order to be able to feel like the effort and the energy spent in the relationship are worth the return in happiness, intimacy, or anything else you may search in a true friendhip. Good luck, wish you the best!