its totally exhausting dealing with depression, (I can only speak for myself) and hope that what I say may be of assistance to you. As you seem to live together, or spnd long time in each others company, it gign to be difficult for him to stay upbeat. EWith my son, I often am diffirent, sometimes, quiet sometimes talkative, sometimes want to be loeft alone and that's my son. I explain to my son that I have depression and suggested he read up on it, so he doesn't take my reactions personally. he has and he's only 19 years old, and now does not take it too badly, although he's only human and only 19, so I'm mindful of my mood changes, and will often apologise or explain how I felt after the moment passes, that's how I take responsibility for myself in reagards to him.
I also isolate and that part is me also taking responsibility, as if I know I really cant be upbeat ad will pull people down, the depression is the thing that's makes us isolate ourselves, as we know all too well, we are not our normal selves and part of the big burden on ourselves is that we feel we are a burden on others, and that they are badly affected by our current reality and cannot cope, so isoloation for me and others who I know is one of the ways we feel that we are protecting others..as we just know that were not good enough t be around right now.
Its very hard to react differently in the moment, if we are low. Yes depression can be a quite self absorbed illness, your spot on, but its not intentional.
Its totally exhausting, you feel it from the outside perspective and your boyfriend feels this ups and downs from the inside , with a weight hovering over all the time. If you feel his behaviour is intentionally nasty toward you then definitely talk to him, if you feel its part of his depression, then get him to see a doctor, who can offer more professional support than you can, maybe you can go to see if you can find someone to offload to also, when things get a lot for you. only advice is do not take it personal.
it may or may not change when he gets job also, it may mean that he just uses up all his happy pretend energy at work, ad is even more exhausted and unable to communicate when he gets in. So definitely gp support for him will be very beneficial.
but bear in mind, I did say I can only speak of this from my perspective, I'm sure I piss a lot of family and my son off, but difference I guess is they are not looking too much from me for emotional support, where as in relationship its different. all the best x