Not sure if you're saying you got fired from the current job. Also no way for us to know if your depression is slowing you down -- does it slow down other things, such as chores around the house or other things you do outside of work? Have you been diagnosed with depression, and if so are you in therapy for it? I would think if you were in therapy this is something that would have come up. You say you loved your job and then lost that love, which could be a sign of depression but it could also be because while you liked it at first it turned out you really didn't like it once you were there for awhile. Lots of people have trouble keeping jobs for a lot of different reasons. Sometimes they are trying to work at something they're just not very good at and haven't found what they are good at yet. Sometimes they really don't like working but have to and it shows. Sometimes other things in their lives get in the way. Sometimes the field they chose to work in has a lot of volatility in demand. We have no idea of the conditions of your work, where you worked, whether you studied to get to a particular job, whether you want a career or just a job, whether you truly like working or just don't. Again, all sorts of reasons why things don't work out at a job, and so while yes, depression can cause this, you would know if it was depression because you would be thinking depressed thoughts and feeling down and lacking energy because of it and it's hard not to notice this because it usually applies to most aspects of our lives, not just work.
My son is depressed and it's super hard to function. He's tired. He's listless. He can sit and do nothing for long periods of time. All part of his mental health picture. remind me if you work with a psychotherapist right now?