Hi NSB, I'm sure you know that your H is taking up a big chunk of your time and headspace and adding hugely to your stress. On your own, life really will be easier and, as you say, you can lead it on your terms (he sounds a bit odd TBH). When is he going or has he (surprise) backed off from that? The sooner the better for you. I promise, based on my experience of 20 years marriage and divorce and 3 children, it takes far less time than you think possible before you reach the point where you think actually life is far far better without the dickhead about.
You have had some great advice from Iam. At the very least, I suggest you do what she says re practical steps. You also need to start building a support network.
Start talking to your friends. This will help you not to be so isolated and start to give you a life outside. It also puts your H's behaviour into the light of day and diminishes his importance. He is really not that great or significant, you just find it hard to see that because of the dark hole you are in at the moment.
I found that even people I knew only slightly beforehand wanted to help and invited me to things. If you need practical support tell them. IME other women love to help out. It is not an imposition (as long as you don't go mad), we all like to feel that we have enhanced someone else's life.
Longer term, build up a plan to help yourself make more friends and contacts. They don't have to all be BFF, but every positive contact helps. Are you in touch with your local autism outreach centre? They often have events and support groups which are really worth attending. Ask your council special needs team what is available.
Two, do you need extra support with childcare? Are you getting all the free help and nursery time to which you are entitled? (sorry, don't know how old your children are). Talk to your social worker. If you push nicely but firmly, for support, often things start to open up (even if it is just an introduction to another local mum). Check out which local colleges are offering nursery nurse or teacher training courses. Often students will love to get something on their CV by helping out, especially experience with special needs children. Even if you don't feel you can rely on them to have sole charge, it can be a great help just to have another adult in the house who can do some stuff under your direction and again stops you being so isolated.
There will be some crap and lonely times, but there will also be happy and even great times and the longer you are away from the man who drags you down, the more happy and great times there will be. There will come a point when you look back on where you are now and seems like an incredibly old, sad and pointless bit of history. Start making it your history and not your future!