I am right here with you. Been training only mma for like 5 months no strength training that wasn't a specific boxing, wrestling or mma technique.
Just did pushups curl and tri extension hard 2 days ago. I can't even lift my arms above my shoulders right now. I hurt so bad yesterday I was almost sick, lol good times, good times.
For my own experience doing mma rounds helps alot with cardio and technique, only strength training with resistance can make stronger.
I don't know if you are a BBer or strength athlete or model or what, but what I do know is that my own strength training has given me a great advantage on the average person. I used to be a 150lb strong small guy, wishing I was 6'200lbs and solid, still athletic.
Now I am 180lbs and even with my older brother in almost every area. He is 6'1" 215lbs as of yesterday.
Get big son!