Please don't give up on making friends - you just haven't found your group yet and it may or may not be the same people you're with in University. See if there's a group nearby that shares an interest in an activity you enjoy. Give yourself a goal of trying 3 activities/groups and attend a few sessions. It's sometimes tempting to bail after a single session, so I'd try to stick with it a few times (unless you're absolutely certain you will never enjoy it).
As others in this thread have said, most other people are too busy and involved in their own lives to think that much about anyone else, so I suspect your concerns about people talking badly about you are very overblown. Don't let your insecurities fill in an imaginary void of what other people are thinking.
Being social is a skill and it takes time to hone, just like any other. You have to put in the time and be willing to put yourself in the vulnerable position of being around new people and accept that you're going to click with some better than others.
Friendships are vitally important to our mental health and I hope you don't give up on forging them. You just haven't found your circle yet, so keep trying!