clutch question

My clutch lately has been acting up, sometimes it works normal but then it freezes and I cannot put it in gear, usually I bring it home in 2nd gear. Also when its acting up it grinds when in reverse and I cannot move it because is frozen. However after a while of resting it starts normal and I can drive it for a couple of minutes and is fine, sometimes it acts up and sometimes it doesnt. I've replaced the master cylinder, check the slave for leaks and also the metal lines which carry the fluid and there are no leaks, I've adjusted the master many times, many ways bled the clutch for pressure. Changed the reservoir and line and still does it? Am afraid it needs a new clutch and that's a big job.I could do it but I have a full time job and a baby and lately I rebuild the entire cylinder head and replaced the headgasket so I dont have any time. Sorry to trouble you.Do you have any adviced and is this normal for my clutch to be replaced?
Thank you.