Feeling so alone!

I feel so utterly alone. Sorry if this is a long post! My 7 year old son was diagnosed with ASD almost a year ago. His school were not supportive of us seeking a diagnoses as apparently he was 'too bright and just emotionally immature'. We paid for the Ed Pysc to visit him in school and both she, the paediatrician were in total agreement and he was diagnosed within 6 months of our first appointment. We had hoped school would support him more but they didn't and said we were using his autism as an excuse for his poor behaviour and he was in complete control and just naughty. Fast forward a new class teacher and he was being shut outside on the playground, in the toilets of just kept in isolation all day. He was then excluded for 3 days. School would not support us applying for an EHCP so we started the process ourselves. However, our happy, quirky boy was now a shadow of his former self so we pulled him out of school and I left my job to home school him until we could find another school. We have now found a new school and moved areas. School have been amazing and he has been there (along with his sisters) since February. He has had a few minor issues and one big meltdown but school have been very supportive and positive. However, he has started to have meltdowns at home again. I know he is incredibly tired but I really thought we had turned a corner. I am supposed to be returning to work and now cannot get out of my contract until January. Yesterday, mid meltdown, he was lashing out and saying he hated me. My head tells me he  does not mean it but my heart breaks when I see him so utterly distressed. The only trigger I could put it down to was tiredness. There are no local support groups so I have nobody to talk to. My husband tries to calm him but he really only responds to me and I am so emotionally exhausted. I have read so many books but just feel like a terrible mum.