I remember reading some of your posts before and how much has happened to you. I too have been in a place where I felt I wasn't moving forward. At the time I was a single mum of two small children with no financial assistance from their father and no benefits. I became very frightened that I might become unable to function and then what would happen to my daughters?
When you reach this stage you really need to put yourself into the hands of your doctor and any other professionals he might think helpful. Take the antidepressants - they will numb your feelings a bit which is a relief from the pain - a breathing space to help you collect yourself. The pain of what has happened to you won't go away because of antidepressants. It's like taking paracetomol for a headache. It will relieve the symptoms allowing time to heal a little and giving you a break from the build-up of never having a rest from your grief.
Eventually the only thing that can heal is feeling heard and understood. Friends can help with this, for me psychotherapy was a godsend. It took a long time and wasn't always easy but it worked in a real, healing sense and was not just pain relief. If this didn't work for you it could be that you are too raw to handle it, or that you didn't open up enough to the therapist. ADs might help you feel less raw and more able to face that treatment. Otherwise you might find a confidante among your friends.
I take a herb supplement called Echinacea Formula, which contains a variety of herbs that help boost your immune system. I very rarely ever catch colds or infections. I also take a multivitamin and mineral supplement daily and try to make sure I get my 5 portions of fruit and veg. I don't eat a lot of processed foods as it puts a strain on your body dealing with them. Another thing that helps is getting out in the fresh air every day, I do my best to walk my son to school and back unless the weather is really foul. Exercise if you can manage it boosts your feelgood hormones. Also I would recommend making sure you do at least one thing each day that is just for you - meet a friend for a coffee, have a long relaxing bath, settle down to read an absorbing book for an hour, etc.
Try to cut out anything you can that's stressful. Avoid people who stress you out and hang around friends who build you. Try to drop any activities that drain you. I know it's not always possible to do these things but do them as far as you can. If you're stressed because your child needs you when he's ill, for instance, you can't do much about that, but if you have a friend who makes you feel depressed every time you see her you can cut that out until you're stronger and can deal with it.
Depression is as much an illness as anything else. If you keep hitting yourself over the head you will get a headache, and if you keep getting hit in your emotions you will get an emotional ache, which is not going to get better until you rest it. You do need to take positive steps to look after yourself to help yourself heal.