Auto Box Driving Me Mad

[Andie520i]

I have a 1995 520i SE with a 5HP18 gearbox and a M50 Vanos engine. I am having a few problems and dont know what is wrong. Firstly the car will not change gear properly and will get to about 4-5000 revs before changing and then when it finally does it goes with a slight bang feel and very sharp.

I had the fluid changed when i first got the car about 7 months ago and it has been fine until last week.

Does anyone have any ideas.

[632 Regal]

is it real cold there?