'Bouncing' is a really shitty Job.
Not all bouncers are enormous gimps.
'Kick him in the nuts' is a pretty fucking infantile and simplistic thing to say.
You survived, didn't get arrested + all your bits are still attached to you = win.
If you work as a bouncer and/or keep getting into fights, you will at some stage get your ass handed to in some capacity. Thats not so much an occupational hazard as an occupational certainty. You'll learn to live with the resultant stress of potentially hundreds of these 'close calls' in your career. Or you'll quit. A possibly wiser course of action since its a really shitty job.
Did you expect that 1 year of MMA was going to turn you into the Batman?
I'll repeat what I said above a different way: You trained. An event happened. You used your training during said event. You survived. You are not in jail. You feel you could have performed better. You blame the system. After a year. Survival = win no jail = win.
Do some weights and train harder.