Hi Ange and welcome.
I agree with Emz your dog will make a lot of difference - i had a staffie, Ben when my husband died -they do give you a reason to get up, and go out,and need caring for.Ben has also since died, and now i take in other peoples dogs for holidays/sickness cover.
Losing your job too must have been another huge blow -it seems totally unreasonable - what do they think youre going to do when a loved one needs you by their side,and how you are going to cope after a loss like that I actually feel angry on your behalf.My husband had a stroke so i also spent a lot of time at the hospital but my boss was much more flexible,and more symapthetic about returning, i think i went back too soon but that was my choice not his.
On that front the only plus i see is that now you know just what hearless people they are,perhaps when you are feeling stronger you can find something working for some-one with a bit more compassion.On a practical front if you are caring for your parents i wondered if you could get a carers allowance, and free up your options a bit -something part time and less stressful.But for now you need time and you need to be kind too yourself, because at this stage just getting out of bed cleaning your teeth and brushing your hair is an achievement.
I didnt realise how socialy inept i was before losing my husband and panic attacks brought a whole new dimension,but i think that has happened to quite a lot of people in this situation so dont feel you are alone with that and dont feel its permanant they will subside -again over time.One trick i learned was to carry a crystal all the time and hold it tight when i felt one coming on. Doesnt need to be a crystal it can be a pebble off a beach a piece of jewellry anything, but something solid, and something that reminds you of a peaceful place so by holding it and thinking of that place you can feel more in control.
My two daughters and grandkids are all the familly i have left now -and whatsapp helps a lot, its not the same as the real thing or physical hugs but it is quite good at lessening the miles between you, so maybe you and your sisters can set that up.
Being here helped a lot, keep coming back, keep writing we will be here for you as long as you need us.