Gear box

Earlier this year a purchased a 2002 Perodua Kelisa, (which is based on the Daihatsu Cuore) I recently had a new clutch and clutch cable fitted.
The problem is that it is becoming increasingly difficult to put it into 1st and 2nd gear. It was ok when I first got it, though I knew it needed a new clutch.
Initially when the problem started it was a little bit stiff sometimes going into 1st or second, then on long trips which were mostly countryside and empty road driving, not much going through the gears, it was fine, but as I got into town and started using the gears, it became a reluctant to go in 1st and 2nd, I was at the front of a busy junction, the lights changed and I could not move, I had to turn off the engine and then it slipped easily into gear.
This keeps happening now, and sometimes it sticks in 1st or 2nd and won't release until I turn off the engine.
Sometimes when this happens and it slips into gear, it crunches and feels like there is something spinning.

I spoke to my mechanic and he said it is probably the syncromesh in the gears and it might be time to get rid of the car.
Trouble is I have had new front brake pads, new rad, had it serviced, new clutch (the labour charge for changing the clutch was £200, ) I have spent £780 on parts and service since I bought it in Feb this year.

What is stopping me going back to my mechanic is that I am not 100% sure that the gear probs weren't already there before I had the new clutch, I'm 98% certain that they started after, (I haven't told him that) but don't want to get him to strip it down just to be told that they put the clutch in ok, and that it is the syncromesh.
Also, when he replaced the clutch cable, which was after he did the clutch, the clutch was a bit 'grabby' and gave a bit of a lurch at times if I was not really careful, I got him to tighten it up and that problem has been ok since. It was then I told him about the gears as I was vainly hoping that tightening the clutch cable might fix it.