How do I become mentally stable without help from any professionals or medication?

There are many healthy coping skills that can help you feel stable without seeing a professional or taking medication. As a disclaimer though, if you are really having a difficult time mentally, you may want to at least consider talking to someone and you should really think about seeing a professional if you are suicidal. If you are just looking for some simple ways to balance out, you are going to have to find what works for you. I enjoy walks, art, puzzles, and deep breathing. You could also journal, exercise, clean, play a game, take a shower, and more. You can just start trying destress techniques until you find a few things that work best for you. Everyone will like different techniques and it is okay if you don't enjoy them all. It is really a personal preference.

I like the phrasing of your question; "without help from professionals or medication", but it leaves space for some kind of help. Thank you for answering this question! Before I say my piece, I'd like to say that each person has their own unique experience, situation, and needs. What works for one, may not work for another... With that said, I'd like to share my experience: In my case, I had very good friends who really stuck by me and helped me depending on what I needed at the moment. For example, I asked one friend if I could call her, just to feel someone else's presence. And we did! Another friend checked up on me often. I also had another friend who was basically like a listener, similar here in 7Cups. My faith matters to me, so clinging on to that helped me greatly as well. I gave myself space to take a lot of breaks too, rather than taking on so much more than I could chew. In essence, what helped me was: social support, faith, rest. For you, I think that it would help thinking about what helps you, and what you need. I was in a really stressful position then, so a break helped. I know some people who needed the opposite - they needed something to do or think about, like dance, art, a game, and so on. So I think one good step, aside from asking this question, is to reflect on yourself and your situation too :)

Be kind to yourself and go easy on yourself. Fix your routine if it isn't in place. Sleep early. Wake up early. Go on walks. Take in nature. Know what puts your mental health off. Know your triggers. Cut off people that you don't need in life. Remember at times, it is about self-preservation. Eat clean and be mindful. Do more of what you love and take on life one day at a time! Also, please know that it is okay to take help from people every now and then. A professional may help you in things that you may not know you need help with. Go easy on yourself.