Workout question!! need advice!!?

I am a wrestler in high school and arm strength is very important in my sport. To build it, my coach suggested we all do 100 push ups in the morning and 100 at night. I tried it for 2 weeks and felt great and now i can do 75 push ups nose to the ground without stopping or falling out of form. I thought this was getting me stronger but my bench stayed the exact same and my arms are still scrawny as ever... what gives? I tried adding diamonds and military and wide grips but nothing...My friend told me that I wasn't letting my muscles rest, so they won't become stronger or bigger. Is this true? if so, should i alternate between 200 push ups a day and 100 pull ups a day? Help please!! I need to get stronger! i'm soo frail