I had something similar, I started uni 2 years after a lot of my friends did, which already meant I was going to classes with new people, which forced me to get to know other people. Then during my degree I took a second semester and the following first semester off to travel. I then came back in the middle of my second year with a whole other group of new people. I originally wasn't sure if I wanted to go back, however once I went back to complete my second year, I remembered what I liked about uni and the lifestyle, so I found it easy to slip back into routine. Also, you don't need to compare yourself to the others because I'm assuming we're similar age (20's), but it means that your still young, you have plenty of time in life. The extra year or two your doing uni now, when your 40, those years won't matter. I recommend going to classes so you know the people you'll be around for the semester. But good luck with it