Severe depression

Ideally you should see a doctor and a therapist. If there is no money for this, some people have success with St. John's wort or Ashwagandha.

I've been struggling with depression since I can remember, but a few years ago it got to the point where I didn't shower every day, didn't clean ever, wouldn't leave my house, randomly burst into tears several times per day, not to mention gained a bunch of weight after I stopped being bulimic. I have been inching out of it since then, and this is how I did it. I don't know that any of this will help you, but maybe give you some ideas. I feel like this stuff is related to weight loss because I personally couldn't stick to a weight-loss plan when I was unbearably depressed.

1. Practice Acceptance and Commitment Therapy techniques. This is helping me stick to a diet and accept the discomfort that comes with intense exorcise.
2. Get some sunlight. 20 minutes a few times a week is a good start. It helps to be somewhere pretty in nature or a park. I started out taking baby steps like that and it helped to get in the habit of exercising as well as some good ol' vitamin D.
3. Learn a new skill. I learned to play a few instruments, but learn a skill that you have been interested in learning. I found that I have learned not only the skill, but my learning style, how to be patient when things don't go as planned, and it gives me a sense of value - I feel like those benefits are helping me stick to my weight- loss plan. MOOCs such as Coursera can be good places to learn stuff.
3b. If you can't think of any skills you want to learn or don't have access to materials you would need, find other small ways to improve yourself. Look at internet resources for new hairstyles, read a few chapters of a good book every day, improve your productivity at work, floss every day. You might already do those things, but the point is to take small steps to convince yourself that you deserve to have a healthy body and a good life.
4. Focus on health more than weight.
5. Be kind to yourself when things don't go as planned. Accepting a day of eating too much or not exercising enough is superior to beating yourself up about it because stress is counterproductive.
6. Speaking of stress - when I quit caffeine, after the two-day long throbbing migraine from the caffeine withdrawals ended, my anxiety diminished by 1/3.
7. Don't look for a quick fix. When you practice mindfulness/meditation, it can take 6 months or longer before you notice improvements. The same with Exercise. 10 minutes a day is a good start! Just do it consistently, and in a month or two, you'll want to bump it up to 15.
8. Take care of your own problems when you can. When I was depressed to the point of not cleaning, it took some time but when I had the energy, I would get on UFYH (look it up if you happen to have that problem) for inspiration and do my best to improve, even if it wasn't perfect. When I burst into tears, I reminded myself that I had every right to have feelings, and that validation helped me feel that I was worth saving. When I couldn't bear leaving my house, sometimes I would walk around the block one time because I knew it a step in the right direction. It is the same with getting healthy. Eat fruits and vegetables when you can bear them. Exercise when you can. Push yourself when you can.

Not sure if others have already mentioned, but i strongly recommend cognitive behavioral therapy. Work on reengineering your synaptic pathways! It works. It saves lives. I'm pulling for you. ❤