Well I have trouble with my 4-seam but that's because I don't throw it very much anymore I use the 2-seamer.
Anyways, that is definetly way too many pitches.
Oh, I be a knuckleballer and I will tell you now that a knuckler won't move unless you get it up above 55 MPH, 38-40 means you're lobbing it. I throw mine 60 something most of the time, sometimes I dip below 60 though to change speeds.
Anyways, you don't need that many pitches, starters at the Major League level have 4 or 5 pitches at the most. Maybe just maybe six but that's very rare.