I really am sorry for your present situation - but I feel, and I know you know, that long-term it is for the best and that you WILL overcome it!!
It's been years since I lived the bachelor life and lived in a few hovels myself - expensive and inexpensive - but I remember when Claire and I first got married and money was tight we would scour the charity shops for bargains - and there are plenty! Claire even managed to pick me a smart suit one day!!
Where we live now, there is a strong wealthy Jewish element, and in the charity shops cheap costing items of real quality are availble, so DON'T be too proud to visit such-like in your area!
Obviously, your social life will be curtailed somewhat, but that's no big deal as it will enable you to save. Pick one night, say a weekend night, when you can go out and really enjoy yourself - but don't be tempted to make it two in a row. Make new friends and rekindle old ones, and accept every dinner invitation you can as, not only will this get you out of your four walls, it'll also save you on groceries because you'll be getting a free meal!
If you can, walk instead of catching the bus. Catch the bus instead of the train. Catch the train only when you have to.
I have a brother who has the ability to cook a wonderful meal out of the cheapest left-overs. OK, he's a qualified chef, but it just goes to show what one can achieve when one puts their mind to it. Don't eat expensive foods when you don't have to. Beans on toast is very nutritious, even if it's boring! And I'm a master with omlettes - another good, cheap but filling food!
I'm sure the ladies on this forum, especially, will be able to give you more sound advice, but the above has helped me and can help you, too.