My social survival strategy in grad school was to quickly clump into a homework group. We'd get together a couple times a week to talk through the work that was coming due. The core of that group gradually transitioned away from homework (as our work diverged) and toward games and movies and other social activities, but the early homework excuse to get together was essential (even though it drove me nuts from time to time).

I have no idea how feasible that looks to you, given your program and your peers. (My friend Will was about 10 years older than the rest of us, but the group worked out for him, too.)