Tax credits help! I am in such a mess!!***Resolved***

Hi everyone, I really appreciate any views you can give me on this. I received a text message from HMRC on the 2nd of October informing me they are sending me a letter regarding my tax credit claim and could I please respond when I receive it. I phoned HMRC that day to see what the letter was regarding. Long story short I received a letter a few weeks ago from DWP telling me I had be registered for a self assessment tax return however I've never been self employed an

**UPDATE** I Thought id come on here and provide people with an update and closure on the situation, as I found myself yesterday CURSING the people that had been through a similar situation and not given an outcome for those that are looking for one. so... firstly Thank you to everyone that gave me advice yesterday and to the people desperately looking for an outcome or reassurance here goes. I have been on the phone to HMRC compliance team today. Absolu