Well, first off, Spiritual Forums is not a place for medical diagnosis and you should see a Health Professional for the physical symptoms. There are many medications available that help with depression as well that may help you to feel better, so that you can feel better. They are there for a reason - God made Doctors too.
Having said that, you can always work on changing yourself. People can change, and it can be as easy or as hard as you make it.
I don't and haven't had some of the symptoms that you speak of, so I don't honestly know what might help you, but I can give you some suggestions for the ones that I have had, and you can try them on for size and see if any of them fit, until someone else comes along who has more intimate knowledge of the others.
Mind Chatter: what works sometimes for me is to breathe. Get connected to you breath - breathing is what keeps us alive, and is our connection to our body - the most basic connection. Sometimes when we get anxious, we forget to breathe, and then our body freaks out. Holding your breath is sometimes an unconscious thing - you may not realize you are doing it.
There are many ways to connect to your breath. Simple counting while you are breathing gives your brain something to focus on. One, two, three on the in-breath, and one, two, three on the out-breath. Try doing this when you are alone, and lying down, so you are relaxed and just enjoy breathing. Enjoy the feelings your body has when you are just allowing it to breathe. On the in-breath, think of breathing in the oxygen, on the out-breath, think of breathing out resistance.
We are energy, and everything the world is made up of is energy, and every particle of everything has a piece of Joy in it. So, after breathing for a while - maybe a few minutes, when you breathe in, breathe in the joy that is all around you - the unseen joy that is in everything, and on the out-breath, breathe the joy down your body and all the way to your toes. Feel how that feels when you breathe in the Joy, and breathe the Joy down into your body.
Another way to stop the mind chatter is to mentally take a step back, from whatever it is you are thinking about. Just leave it where it is, and step back from it in your mind. And just let it be. I am learning to do that, and for me, it is very peaceful. Just a breather, for a few moments, and it resets my mind chatter - sort of turns off the chatter and I forget what I was thinking about.
Feeling better - sometimes the only thing I can do to feel better, is to reach for a little better feeling thought than the one I am worrying about, and go general. This is an Abraham (Hicks) process, going general. Say you are worried about some person who was mean to you. So, you take a step back from the thoughts, and be quiet for a moment, and just breathe for a few minutes, and then breathe in the Joy, down to your toes, and then try to think a little better thought about that situation.
The one thought that always helps me is, nothing has to happen this red hot minute. I can sit for five minutes and think of something that does feel good, and focus on that for five minutes. Try and think of something that is a good feeling, or a good memory, or some place that you know that is beautiful, and try and do that. You can do that for five minutes.
After five minutes, you may have another thought that intrudes, and when that happens, it's okay, just let that thought go, and think of something else that is nice to think about for another five minutes. You can do five minutes.
Then repeat that again.
After 15 minutes, you should be feeling much better.
It will get easier to get to that calm, centered place with practice. You are teaching your body that it doesn't have to react negatively to your thoughts, and that you can control your thoughts anytime you want, and you can relax your body any time you want.
If I am down, I have shortcuts now that I do, if I have a quiet place and the internet. I just go to You Tube and watch something that makes me feel better. I like watching babies belly laughing, and cats and dogs being silly, and comedians. Sometimes it will be Jimmy Fallon and the Tonight Show - there is usually something stupid on that can make me laugh.
And if you do that every day, for a little while, just to make yourself feel better a little bit each day, each day you will feel a little bit better. It may take a week, it may take a month, but it is worth the effort. You are always worth your own effort.
Be easy, and don't beat yourself up. Be yourself, and learn who that is, and don't let anybody tell you that you are not worthy.
Google self love - and check around. Focus on self love for awhile. There are many ways to learn to love ourselves.
I don't know if you even know who Abraham Hicks is, but there is this you tube audio that always makes me smile, so I'll put it here. Abraham is a group of entities that Esther Hicks channels - she has been channeling them for people for over 25 years, and they have an awesome sense of humor. So, I hope this makes you smile.
Get Happy
https://www.youtube.com/watch?v=ykAPG_Ap7cY