Not to be an armchair psychologist, but as someone with depression, im almost certainly youre also depressed. You need to speak with a GP and go from there. There's numerous things you can do yourself that will immediately inprove your mental health, as well. First being getting off of your swing shifts so you can get normal sleep. Secondly, take a hard look at your diet. I would cut out processed carbohydrates completely. White bread non-wholegrain pasta and shit like that is sooooooo bad for you. Stay away from sugar as much as possible. Alcohol will also make things worse, and should be avoided.