Also wondered if they state in the letter that it's about employment, can it be about anything else or is that all they can/will investigate me for? Really appreciate any advice as all this is really making me very ill!

Hello, I'm new to this forum but have been reading posts often and could really use some advice! I'm a mum of two children one is 3 and one is 5. Last week I received a letter to say I am requested to attend an interview under caution as they believe I have committed a criminal offence in regards to my employment. I am no longer claiming benefits as I have moved back in with my babies dad. I took a job last year whilst I was claiming income support, and I worked there for 10 weeks, I only took the job as a trial because my little boy has ADHD and possible asd so he can't cope with change to his routine. I hated being on benefits so really wanted to work but it became quickly apparent that it was affecting him and I had to quit. Since receiving this letter I haven't ate or slept, I feel physically sick! I thought that I was allowed to work up to 16 hours when I was on income support but since receiving the letter I have researched it and now realised that I must have declared it. I'm so scared that they will make an example of me and send me to jail. I have a tax credit investigation a few years ago and it was settled as a civil investigation and I have a direct debit to pay it back, but can the dwp use that against me, and will a court use that as I have committed fraud before, or are they not allowed to throw in something thats already been dealt with? I'm also worried now that I also didnt inform tax credits at the time of the job so will I also be in trouble with them to now? I have paid a solicitor to come with me on Wednesday but I can't think of anything else, I'm so scared! Will be grateful for any advice please!!!