It was really helpful to hear your story. If it helps, I've been depressed/on SSRIs for about 2.5 years now and I struggle on and off with feelings for my partner. I get really acute relationship anxiety, which can get really bad when we are alone together for long periods. Space does help, but I know how hard it is to ask for it. I know if the tables were turned that I wouldn't take it very well, but maybe your partner will surprise you. Although we've been together a long time (almost 6 years), me and my partner were long distance for quite a long time (like 3 years) and now we live separately. People think it's weird, but it's our choice and it suits us both at the moment. It's especially helpful for me in terms of managing how much space I get. Because it's not just space from him I need. I used to be the life and soul of the party, visiting friends all the time and wanting to be social and go out. Now I stay in almost all the time and find it difficult to muster the spoons to be around others. It's super weird. I think I've learned how to be on my own for the first time in my life, which has been a real gift for me, but there's definitely an effect of the meds on how I relate to others against the amount of space I need these days.
Given some of the new information I've found from this forum and other places, I've decided to do my best to hold on and not make any decisions until I'm way off the meds. I'm hopeful that my feelings will return, along with a lot of other aspects of my personality. I try to do loving things for my partner and try to be honest without being cruel. I also try to be realistic about what I'm capable of and try to be grateful for all the support and love that my partner gives to me.
The only thing you can do in this situation is be honest with your partner, maybe explain that your experiences with antidepressant withdrawal are making it difficult to be around others and maybe try to figure out between you how you could get some space, which will be really helpful for your recovery and in the long term, will be good for the relationship.
From March 2014-May 2016 20mg Citalopram daily. Tapered to 10mg daily around May 2016 but couldn't continue due to withdrawal symptoms. Currently trying to quit, right now on 5mg/2.5mg every other day. Most severe symptoms: severe depression/suicidal ideation, anxiety, extreme lethargy, cognitive impairment. I hate my life right now.