Hi Walkden and welcome to DWD.
I'm glad you found us, but sorry it's because you are feeling as bad as you are.

Firstly, please go and see a Dr - even if you print off what you've written here so you don't have to say the words. Get your meds sorted and sort those abscesses - you must be in so much pain.
WRT your meds - right now you are going to be feeling absolutely awful - how long have you been off the venlafaxine?