Benefits

Hi. New to this my husband was off sick from last Apr 2017 due to dystonic tremors and he also has MS. He got sacked in Dec because he put the wrong date on his sick note. They have not once been in touch since Apr to see how he was etc. He is taking them to a tribunal for unfair dismissal.
He gets reduced UC due to my part time wage he also applied for PIP which was horrendous the assessor asked us to get on as she was running out of time. The report came back with zero it was like they were talking about another person. We have gone for mandatory reconsideration and wrote a letter too.
I do have a question and just wonder if you know anything about FSM. I get paid £663 a month along with my husbands UC as of April they have put in a treshold of £7400.. We are going to be over this so my son who is in his last year of primary won’t get it when he moves to secondary which is really going to hit us. Everywhere I read they mention the £7400 treshold as well as a income of between 18000 and 24000. Although we are over the 7400 but will not earn 18000 even with benefits. Will we loose FSM?
Thamks