How do I improve my pitching speed?

I am a 14yrs old freshman. im 6'1" and 185 Ibs. I'm mainly catcher I was told I was the best in my cbc league. I average in the low 80's now but would like to be in the 90's if possible by march to increase my playing time on Varsity. I average about 6 home runs a season by swinging a sledge hammer everyday, but I have yet to find an effective way to help my ball speed. Any ideas?