Clutch/transmission/shifting issue

I replaced clutch, pressure plate and flywheel. It ran great for two months, then I backed out of parking space and would not come out of reverse. After a little muscle I got it to release and started to drive it home. Well it got stuck in reverse again. Took to my mechanic. Not quite sure what he did but said it was fixed. Went to drive it home and it was whining in all forward gears. Like a manual transmission whines in reverse. It had never done this before. It was hard to shift then after one mile it would not shift any longer. Seems like pressure plate is not engaging or disengaging. I am no mechanic but know somewhat how a clutch works. It is the same guy who did the clutch and I think he did not do clutch job correctly. Please can anyone help me out.