Inability to Make Friends

Ive struggled with friendships for a few years now. I used to have best friends in elementary school and middle school. Freshman year I started dating a boy and that lasted a year and a half. In that time, I lost my best friend (due to personalities clashing.) After that, I never really felt close to anyone in a platonic way. Ive had friends but I dont like confiding in anyone. Lately going out and making plans with people is just a burden. Ive gotten out of a seven month relationship about a month ago and Ive been dealing with severe loneliness. I isolate myself but I just dont feel close to anyone I know and I dont want to get close with them. Just havent found the right friends. :/