I have twin autistic sons....one is mild and the other is more severe

I am a single mom with twin autistic sons who are almost ten they are my world......they were fine until their two year old vaccines and then Brock lost all his speech so i know it had something to do with the mmr vaccines....Breven is mild he talks and both of them are highly intelligent.....they are in different classrooms seeing that Brock cannot communicate as well both are in self contained Autism classes....i adore their teachers but where we live there are no aba therapists and this upsets me......i find myself stressed due to the fact that Brock has been having severe meltdowns.....pulling his hair out and almost like he is regressing please if anybody knows how to help me give me advice please do.....Brock is in speech but im trying to get him more....their dad is not a big part of their life he sees them four days out of the month i have a degree in working with special needs children but when it comes to your own it's hard....also brock has major sensory issues especially with food....has a poor diet i give him supplements and vitamins...but it makes me feel like a bad mom when we go to eat out and i have to bring his food he loves spicy foods chips etc......sooo in a nut shell please help me with any advice you can and is anybody else going through this....my boys are my world and a gift from God i just want to do whats best for them..........