Is it possible to be jet lagged without traveling?

Okay so, I have a super messed up sleep schedule. One night I’ll sleep from 3 am to 3 pm. Some nights I’ll sleep 3 am to 12, if I have work I can wake up on time but I can’t fall asleep till 5-7 am and sleep for 12-18 hours a day. I’m starting to wonder if I’ve messed up my internal clock so much that Im experiencing prolonged jet lag? It’s been like this for a couple years now. I just wrote it off as I’m a long sleeper and need 10-14 hours of rest a night. But if I try to wake up at a normal schedule like sleeping 8 hours waking up around 10 am I’m exhausted and out of it despite getting perfectly fine rest. It’s honestly debilitating. I also do struggle with depression, I’ve never been diagnosed with any sleep disorders and if anything I’m sleeping too much. I don’t make much money and I don’t have insurance so doing a sleep study or going to the doctor isn’t very approachable for me at this point in my life. Does anybody have any advice?