I'm in a similar position. While I'm only 24 and only recently diagnosed (Depression diagnosed for a year, but I know I've been dealing with it for around 8 years). I have been on and off with my boyfriend for about 4.5 years (we had a 6 month break, as I was going through what I think was an episode; I needed someone there for me and he had too many of his own issues to be able to be there, and I unfortunately ended up having an affair)
Anyway, we are back together again, and have been for the last year. We also live together. I am finding it so hard to act rational or real explain to him what I'm going through.
It takes a really tolerant partner. At least he does understand I need to be on meds, but sometimes I wish I just had the right things to say to him, how to handle me.