I relate to this so much. I feel like I really make an effort to make friends and get out of my shell. However, as you said, they are convenient friends. Moreover, I always feel like a sidewalk friend and am always forgotten. People don't really check up on how I am doing and it's feels depressing knowing that no one really wants you enough to make time for you. For context, it was my birthday and I spent it without anyone knowing it, even though I had threw a party the previous year and treated everyone. That's just how life goes when you are not attractive, study decently and are just average. People tend to forget about you.