Sunday anxiety before work on Monday

Since I was four, every Sunday before school I would without fail have anxiety and a ‘tummy ache’ and dread the week at school. Now at 31 I still get quite extreme Sunday dread/ anxiety even though I’ve finally found a job that is nice and suits me. (I have autism) I think it must be the transition but it’s just so annoying to need to ‘get used’ to work again every Monday. Nothing has changed from the Friday where I was absolutely fine! Just the space of two days! I was awful after two weeks off over Christmas and actually caused me to have a panic attack. Any one else? Any advice?