You're taking in too many calories overall. It's not really a fat burner the way some imagine, though it does increase fat oxidation. At 12 mg, is your hunger still strong? If it is, you could add some cagrilintide. Before that, try a week cutting calories to around 1800 and see how it goes.
Trying one more time to understand why RETA effects have stalled. I'm 50, 6'2", now 282 lbs after starting at 314 in August and beginning RETA on Oct 4 at 308. Background includes rugby, wrestling and other land-based sports, with injuries reducing activity but not making me sedentary. My body feels fast and fit in the 235-255 range. RETA worked well from Oct starting at 0.5 mg up to mid-December at 5 mg, getting me to 282 with little effort. Since then progress has flatlined at 12 mg. Typical diet is 6 eggs to start the day with a couple coffees using coconut sweetener around 700 calories, lunch protein shake with 2 scoops for 60 g protein at 240 calories, some beef jerky at 200 calories, and a meat-based dinner around 1000 calories, totaling about 2200 low-carb calories. Blood work twice showed low estradiol, low cortisol, low DHEA, and low B12. I've been supplementing extra B12, adrenal cortex, and DHEA for 3 months. Everything else looks solid. What changed includes a new RETA source and a two-week pause around Christmas that added 9 lbs, plus starting IPA and TESSA while titrating RETA further.