I'm fat (170 cm 102 kg). I go bouldering about 3 times a week.
It's a lot harder when overweight. I haven't progressed as fast as everyone around me, and it is frustrating watching people who aren't overweight climb for the first time because they typically can do things I can't. It's also extremely fun and addicting, and everyone that climbs at my gym tends to be supportive and not at all judgemental.
Hang in there, and consider trying crack or face climbing. One of the best wall climbers I ever had the privilege of following around was overweight (despite playing soccer and running and everything else). He couldn't boulder for crap but he had great balance and body english.
It's a lot harder when overweight. I haven't progressed as fast as everyone around me, and it is frustrating watching people who aren't overweight climb for the first time because they typically can do things I can't. It's also extremely fun and addicting, and everyone that climbs at my gym tends to be supportive and not at all judgemental.