As someone who was on Paxil and many other SSRI's, they are relationship killers. Although it is an AD, Paxil is extremely useful for anxiety and is approved to treat social anxiety. Your bf's withdrawal symptoms sound identical to my side effects when I was taking Paxil: apathy, low energy, low sex drive, isolation, lack of interest in anything, really. It took a huge effort to hold a conversation and I never showed any affection to my h.

His withdrawal sound like my side effects: depression. This may last a couple of weeks and get progressively better with time. I have heard that of all the SSRI's, Paxil is the worst to come off. I understand this must be very painful, just try to keep the perspective that it is most likely depression caused by coming off his meds and has nothing at all to do with you. I know it is easier said than done, I'm sorry you have to experience this.