Hello alexisonfire94, welcome here. I am going to be direct on this one...I don't think it is helpful to throw around labels for mental illness when someone has not been in touch with a professional. It sounds like you both may have been looking up symptoms and seeing if they fit his behaviour, which is a recipe for disaster as it is guesswork, and doesn't help you to deal with the problem behaviour. The only way to know is to see a professional and find out, and look at what options there are for treatment.
So where does that leave you if he won't seek professional help? Well either way, you are in a relationship where there is behaviour causing you problems. Whether or not there is a mental illness in play, you will both need to sit down together and work through the specific issues and how you will deal with them. Couples therapy might be an option in this regard.
Issues you might discuss together: his anger and depression about his job, his unwillingness to do anything about it, and how that affects you. His desire to leave you and go travelling, and how that makes you feel. His dissatisfaction with life, and how that makes you feel about your life together. Are you seeing a pattern here? While you can't make him seek help, or change his behaviour, you can make a decision about how much you are willing to put up with, and give him the best opportunity to see how his behaviour is affecting you.
A diagnosis won't change the core problems happening in your relationship that you are describing, that is work the two of you will need to do together.