I used a belt for awhile...when my muscle was weak after spine surgery. But it really only cut off my breath. Something you can work toward.... is to thicken up your lower back.
Your new butt machine should help you with that...[by the way, lets see a picture of the model?] You can work your lower back and butt safely at the same time.
It may take you like 6 months jrt. I grew a much stronger ,thicker [so my spine divot is deep] in about 6 to 8 months with the help of a great butt machine and doing slightly bent knee dead lifts with my abs tight...and my head up [short range of motion]
My waist size did get bigger from it... but not in the oblique area... my waist is thicker because my lower back is thicker.
Be careful with the weight honey, your training alone and the muscles want to go go go go...but the skeleton says no no no.