I've come off Citalopram a couple of times now, and back on them now.
The biggest thing I found is take it slow. It shouldn't be too bad as it's been a couple of months - I was on quite a heavy use for a couple of years before coming off. It was a staged withdrawal, going to 3/4 of the dose as you mention for about 4 months, then 3/4 of that dose, etc. I had it in liquid form for a while, due to an operation, which also made it easier to measure the dosage (because breaking up a tablet into 3 pieces is practically impossible, and very messy *lol*) Definitely worth asking the GP what they recommend :-)