It sounds like home ed could suit your son really well, since he is so much happier when not in school. He's been at school for years now and by the sounds of it, school has never worked for him.
One important thing to know about home education is that it doesn't have to be forever. It isn't a permanent commitment and isn't the huge deal people often make it out to be. You can try it and see how it goes. Some families home educate their special needs children for a few years while undergoing assessments and securing an EHCP in case they want a return to school later. Some kids may find primary school overwhelming but are okay at secondary, or the other way round.
So I don't think you need to think long and hard before removing him from school to try home ed. What would you be risking; what's the worst that could happen?
As for where to start, experienced home educators tend to recommend starting with a complete break from any adult-directed formal education, especially where the child has had a traumatic time at school. Give your child time to recover and be happy again. Let him play, read to him if he wants you to, talk to him, take him to the park, bake with him, play games together, take him to visit relatives - whatever cheers him up.
By law, you have to be providing an education from day one, but it can be informal and child-led. if the Local Authority ask about the education, you can write a report mentioning all the learning he has been doing through daily life. You can get help with this from other home educators.
That is what I would suggest. While your son recovers from school, you can explore different educational methods and maybe talk to other home ed families in your area to see what activities and social meets are on offer, though your son might not want to do anything like that just yet.