Carina in trouble... help needed please

[Toyotagirl_uk]

Hello,
I've had my 1994 'L' reg Carina E Auto for 2 yrs - great car but recently I'm having major problems ...
At VERY low revs she stutters and has cut out on me - I've had her in the garage twice in 6 months - they cleaned out the throttle body and the sensor but 2nd time round it didn't work :(
Only way I can describe it: if driving a manual and you get to an almost full stop but forget to dip the clutch - the car stutters - its like that - if I keep the revs up she's ok, if I use neutral at junctions/lights she's ok, and I've started using '1' for parking etc with little problem...

She doesn't seem to like 1st gear - she a bit clunking going up from 1st into 2nd.

She drives well apart from this - although she's 22 yr old I've only got 68,000 on the clock - she was garaged and well looked after prior to me buying her and the only problem I had last year was the original radiator had to be replaced.

IF anyone has ANY ideas I would be very grateful as I can't find anything online about this problem - Is it a possible oil change (although the garage said it was a sealed unit) ? - is the gearbox is going? or just the sensor? (plugs and filter changed about a year ago)
Many thanks 

Suzi