I feel like I’m doing something wrong

I don’t seem to be losing as much. Little back story- I started me weight loss journey a year ago. I was at 303 and cw is 257. I started off taking phentermine for 3 months and got to 270. After that, I could only lose 5 pounds on my own (265) and decided to start sema. I’m in my 4th month, just doubled my medication last week to 1.5mg and have only lost 8 pounds. I still feel hungry & don’t get full quickly. I feel like I only felt the affects of the medication work correctly at .8 mg for the first 2 weeks I was in that dose. But it seems weird that at 1.5 I’m not feeling much. Do I need to increase my dose? Is it something with where or how I’m injecting? I inject in my stomach at different spots each time, which has plenty of fat and make sure to avoid stretch marks.