1999 Honda Accord CLUTCH

1999 Honda Accord 4 cyl Wheel Drive Type unknown Manual 168000 miles

I am having problems with my car, its a 1999 Accord Ex, 168,000 miles, 5 speed, 4 cyln, The problem is that if I have my car in first gear and let go of the clutch it will not stall, I will move forward. It does not pick up speed as it should, its going about 5x slower than normal. It turns on good with no problems but when I start to take off and I put it in gear it like over accelerates and goes really slow, this happens when shifting into all gears. It started off just feeling over accelerated and then it started not wanting to get the gears in right. I called a mechanic that said it sounded like it would be the clutch, I wanted to make sure that in fact it is the clutch before I make such and expensive repair. I have a friend who can fix it but does not know if he would need to take pull out the motor in order to replace the clutch.?QUESTION: Could it in fact be the clutch? Is there anyway to maybe adjust the clutch on this type of vehicle? Would the motor need to be pulled out?