Need advice on teeth retainer issue.

I had an overbite due to which my lower teeth constantly touched the back portion of my upper teeth which resulted in grinding and sensitivity. I wore braces  which corrected it. After braces, the orthodontist put a fixed retainer on the back side of both upper and lower teeth , and a removable retainer for the front part of both upper and lower teeth. The problem is that the fixed retainer on the back side of the upper teeth keeps breaking. I have already repaired it thrice. My lower teeth keeps hitting the upper fixed retainer even after ortho checking the bite and doing smoothening of the teeth. I have researched a bit and there are removable retainers available which support both back and front teeth. But when I asked my dentist, not possible. Pls let me know if it's possible to go for removable retainer which will support both the front and back of upper teeth, and continue the current setup of fixed and removable retainer for lower teeth. Should I see a different ortho