Indentation on forehead after botox - advice? (photos)

I have been having Botox for about 6 years, in the last year or so I now have developed 2 long indentations down my forehead. It literally feels like my skull is coming apart. It’s very noticeable in the day light. I can run my finger along it from the top of my brow up to my hair line and it gets deeper and almost squidgy. I had a 7 months break from Botox which is where I noticed it even more, done some Botox but it’s now getting even more noticeable