If ADs are not right for you then that is fine. Would you look at counselling or CBT? You may be able to get this free through your doctor or charities and I do think that would help.
Apart from that, could you begin to look at the various things which are dragging you down - which seem like a perfectly sensible list by the way - and start to plan how you might tackle these one nibble at a time?
Take your mum: has she had an assessment by adult social care? If not, start pressing for one; are there local AGE UK or other pensioners groups or are there local charities who could help (fabulous volunteer drivers took my mum once a week to a coffee morning for OAPs for example), would a neighbour pop in now and again in exchange for a small payment (I paid a local SAHM with small children for two half hours a week, just to pop in for coffee and let my mum enjoy the company and talk about the children - that worked for both of them), does the local sports centre have OAP sessions etc - some do special seated exercise sessions or swimming sessions. Once you start to work on tackling problems bit by bit they don't seem so unbearable.
I also agree with the PP who said make yourself go for a walk every day whether you want to or not. Go to the park and people watch as you walk, take time to enjoy the experience and breathe deeply. Aim to build up to half an hour's steady walking a day - it will do your mood the world of good (at least it does me!).
Sorry, it all sounds a bit preachy, but IME the more you start to take control, the less anxious you will feel.