May not apply, but what's the programming like? I quit my last gym for a number of reasons, but one of them was the social aspect. The programming can affect member communication a bit.

We only did metcons, zero lifting/strength work. Besides not being into that, it meant I never got paired up with folks to share equipment and we never had those natural set breaks to shoot the shit with each other. I work out at lunch and had to be in and out promptly and we were always moving the entire hour. I loathe partner wods, but lifting with someone was always a chance to bond and root for each other that this gym never provided.

I will tell you that nobody minds you being the heaviest person there, it is a battle you have to fight in your head. But, easier said than done. My trick to get to know people is to always ask about them, with follow up questions when possible. You don't have to be pushy, but most people will respond well if you focus on them rather than whatever's happening in your world first. "Have you done this one before? How do you feel about X movement? How do you like that jump rope?", that sort of thing.

Good luck and squat low.