One of the most important things you can do is fix your sleep schedule if it's messed up.

Practice sleep hygiene: Dark room. Comfortable bed. Sleep at the same time. No electronics one hour before bed.

Basically start getting yourself ready for bed an hour before you're ready to sleep. Melatonin helps a lot with this and it really has no side effects as long as you take it when you want to go to bed(not randomly during the day and night).

See if this helps. Another thing is to have multiple hobbies and things you look forward to so that if one thing on your plate isn't doing well you have multiple other "good tasting" things in your plate so you don't dwell on things. If these things don't help you have a few days you should go see your primary care physician or a psychologist and they can help you more. They may prescribe you some therapy and won't immediately place you on medication.

However, if you have significant weight loss and loss of appetite or suicidal thoughts etc., you should probably try to seek professional help sooner and ask them for some support networks if you feel your current support system isn't enough. The hardest part is accepting that you need help but if you have these signs know that they're serious and it's not your fault and the doc can help you.