Hi Paula, UK member here too, not too far away in the south west. Was a witness for many years but stopped associating about 3 years ago.
Sounds like there are two aspects to your story. Number one is that you have had a lot of trauma in your life, and you have needed and still need help to deal with that. Which led you to number two, studying with the JWs partly in order to get help with things.
You are absolutely right in your assessment of the Witnesses. The bottom line is that they want you attending regularly and progressing swiftly towards baptism, as once you are fully in they can then apply pressure on you properly. All the while you are just studying or an 'interested person' or a Memorial attender, you can just walk away and they don't have any hold on you. They want you to join fully, get their numbers up, be a 'success' story for their efforts in the ministry. And then the organisation can control you more effectively.
So it's a damn good job you didn't get baptised! You have avoided an awful lot more pain and heartache in the long run.
Firstly then, you need to seek PROFESSIONAL HELP with your problems in life. Elders and other JWs are NOT professionals, they do NOT know how to help people effectively in any way at all. All they know is what the Watchtower literature says, which is mainly nonsense or things copied from other sources. There are medical professionals who can help you with your panic attacks/agoraphobia, with your drinking problem if you still have one, and with any emotional trauma related to the loss of your mum or your friend. Go to your GP, explain everything, they will be very sympathetic and put you in touch with the right people who will help you properly. And there will be no hidden agenda from them.
Secondly you need to sever your contacts with the JWs, they will only try and discourage you from seeking medical help, and try to get you back in with them. Even now you are feeling anger towards them which is taking up your energy and occupying your mind. Your focus now needs to be on yourself and on your son. Get yourself emotionally well and happy again, and you will be making a better life for your little family. Then you can look forward and work out what to do in life. But you need to look at your problems and get help with them first.
And see if you can get in touch with any of your former friends, ones that you trust and could talk to. Explain to them what happened with the JWs and how they encouraged you to shun your friends at the time. The JWs get us thinking that everyone outside the congregation is dangerous, well you know that isn't true from the past, but it can still play on the mind. Make new friends, meet up with old ones, start building yourself a new life outside of the witnesses again. So many here have done it, and are happier than they ever were before :)
PS Years ago I used to conduct a Bible study with a young mother who suffered from panic attacks, yes I know I should have handed it over to a sister but studies were hard to come by in our territory! >.< This young lady suffered terribly as she tried to attend meetings and come on the ministry, I really tried to encourage her as much as possible, but it was awful for her, her palms would sweat profusely even on the way to the hall let alone sat inside, which made her embarrassed and so it got worse, until she couldn't cope and had to walk out, which was even more embarrassing, etc etc. I'm sure you know how it goes. She managed the ministry twice I think in total. In the end I think I stopped the study as it wasn't getting anywhere, and she really seemed to become a lot happier again, thank god for that in hindsight! So I know how hard that can be.