As others have said, there are options that are between full on HE and a mainstream school. Are you in touch with local home educators? Are you on the national FB groups? These are probably a better place to help you work out how to move forward than Mumsnet.
Just like mainstream doesn't work for everybody, home ed doesn't either. Your first step would probably be starting the process to seeking diagnosis' as required and looking into an EHCP which will enable you to seek an appropriate placement for both children. Does your county have a support service for those with SEN? My county does and you can call them to find out about all sorts, including about alternative provision that is available locally. I'd say speak to somebody about AP availability before speaking to the LA, as the LA will often push people to go back into mainstream and not really want to discuss alternatives, whereas being aware of any AP settings before speaking with them will put you in a better position to ask how to access one of those settings, as the LA can fund them.
If your kids have additional needs, putting them back into the closest schools may well be a disaster, I wouldn't apply until you know what they are able to provide for your kids needs. In my county we have numerous mainstream schools who are better equipped to manage those who need additional support, some have 'hubs' within the school so they children have a place to go when overwhelmed, or they have classes within the hub but on a mainstream base school, even without a formal diagnosis, but they aren't always necessarily the most local option. So, if you're going back to mainstream, it may be worth investigating if something like this exists before applying. And ask on local FB groups about schools and how they support kids in the area, I've met so many kids who've had to come out due to lack of appropriate support and are unable to access school again, but a school who do it right are worth their weight in gold and parents will happily share stories of both if people ask for recommendations!
If you want to continue home educating them you need to find something that works for you, doing school at home doesn't work for many of us for various reasons, there is a vast range of HE styles, and a huge spectrum between parents being in charge of a school at home experience and completely child led experience.