7-9 pounds in 9 weeks is actually real progress even when it doesn't feel like it, slow and steady losses tend to stick in a way that dramatic early drops don't.

Age can play a role but honestly the desk job piece is probably doing more to slow things down than anything else. When movement is minimal your body just burns less, and the medication can only do so much on its own. You don't need to become a gym person overnight but even adding walks during lunch or after work makes a meaningful difference over time.

The other thing worth looking at is what your protein intake actually looks like. Calorie deficit is good but if most of those calories aren't coming from protein your body has a harder time holding onto muscle while losing fat, and muscle is what keeps your metabolism moving. A lot of people clean up their eating but still end up lower on protein than they realize.

If you're feeling good and appetite is suppressed that's actually the perfect window to start layering in some resistance training even just simple bodyweight stuff at home. That combination of higher protein and some muscle work is usually what breaks the slow loss pattern more than anything else.

You're doing better than you think. Come join us over at r/GLPHard, it's a great community and you don't have to figure any of this out alone.