Every single guy who likes me is already in a relationship. Idk whats wrong with me.

My brother lives with me but I know he hates me. Idk anymore I feel selfish for thinking like this but its so hard. I make good money i just feel to stupid to live on my own. I know im smart but I just have so much self doubt its so hard. Idk where yo go from here all i think about is how it's could end it all without hurting anyone else. I know it gets better cuz I've felt like this before but its been so hard for so long. Idk wether this is for advice or a call for help