Hitting a plateau, and how do I fix it?

Hi I started my journey last year and I lost quite a few kilograms, Now it seems that I have hit a plateau, meaning that I have stayed the same weight for about 3 months without losing anything.

I want my old body back. I don't really eat junk food or sweets or any sugar drinks (soda). I do my regular exercise which includes HIIT 3 times a week and 2 days of strength training.

I don't know what to do to get myself out of this. and it feels the longer it takes for me to lose weight the more unmotivated I get.

I need your advice on how I could tackle this problem.