Dumble, So sorry about that nasty relationship and the abuse you suffered. If only they knew what it actually did to you. Obviously there was no care at all and you are left to pick up the pieces of your life as best you can. From what you have written I have no doubt at all that therapy is by far the best solution for you as you know the cause, what happened and how you reacted to it. It is those freelings you need to deal with and of course it's not simple or easy as our minds are affected by such abuse. We can never forget such and can only deal with it by talking it out and understanding how strong you really are. You have a healthy relationship now so that shoulod give you strength to dig up those fears and horrors with a therapist and talk it through.
Cognitive behaviour Therapy is my preferred therapy these days but firstly you must know what it is you are dealing with and have it all out in the open between you and a therapist. That word, therapist is actually horrible in this context and I hate using it but it's the name of those that do therapy isn't it?
No one wants to take medication for this. I don't b ut I'm prepared to if needed as I will not let it take me over if I can help it. Medication is a hit and miss thing though in trying to find what's right for you. Paragraph 2 of your post says it all really. Panic attacks and depression so anxiet is in there too. Panic attacks can be so dreadful, a true horror.
I haven't had depression as such but am on the verge maybe after losing my wife recently. She though was depressed for many years and eventually controlled her anxiety and depression using Effexor. Nothing else seemed to work other than briefly for her. Of course if it causes other physical problems then it's a very hard decision isn't it? As far as putting on weight goes, medication doesn't do that at all. It stimulates your appetite and causes you to be more sedentary than you were and you choose easy food rather than good food. That's where the weight comes from, what you eat. If your digestion rejects the medication then no, you couldn't gain weight, or lose it unless you persist.
You ask about herbal remedies and so on. There are more than you could count I'm afraid and the evidence is they do not work generally. If they did do you think all the people on this forum would take medication, or most? Of course they wouldn't but they do simply because the alternative market is generally fraudulent and does not work at all. Some will say it helps. I say, so what, does it stop the pain etc? If not why use it?
If you are truly going to deal with this thing you must learn to be open and honest about it. Groups are not essential and many of us would never go to one. Therapists though, you learn to trust them and that's the way through the forest. Don't forget to look up CBT. How I deal with it hasn't been experienced yet, I'm in limbo waiting to start feeling something really, first time for me. I wish my wife was here to answer you. Not sure what she'd say but it would be about accepting what's wrong, deciding to seek help, accepting help and working with the medical people as much as you can. Always do what you agree to and if you need to change, ring the doctor etc first and get advice. Self medication is the way to misery.
One thing I know she always said to people is "The answers are withing you, nobody else." So that's where you look, inside with a therapist. Filth it is so dig it up and throw it away, figuratively.