I'm a bit surprised that they tossed you in with the wolves so quickly. I'd politely insist on working on conditioning, shadow boxing, bag work, and maybe some light sparring for a couple of weeks. If they aren't interested in easing you into their program, then I would not return to a place that may have little concern for your safety.
As far as Muay Thai and Aikido; I think it's a great idea. There isn't much out there that will efficiently hone your timing and distance to a point like the threat of being kicked or punched in the face.
