GenCat is totally right of course. Focus on you.

I had the same experience at varsity. Depressed as hell, wasted loving an idiot, zero friends, so lonely, failed failed failed... And all for a degree that I eventually finished and is useless. Kinda wasted 4 years of my life there. Also I tried to commit suicide, and not the 'call for help' kind, the 'I want to die' kind. Desperately unhappy.

Now I'm back at varsity for a new degree in a class with people 4 years younger than me, but I couldn't be happier to be honest. As for friends and love interests, there will be many, and the next bunch of people you befriend probably won't last forever either, because you'll meet new ones soon enough after them too. This is life.

My point is, whether you waste/repeat a year or even 4, don't let that define you. It gets better, you can be happy and it will be worth the wait. Don't compare yourself to the people that are graduating, not everyone follows the same paths in life. You should be your only competition, focus on getting better and everything else will follow.

I know you're feeling like hell, and you could probably create a counter argument for every piece of advice given (I could have when I felt like you), but I'm speaking from experience and I have felt what you feel so many many times. But you could be happy, and that's all that I want you to know.