Plateau advice

Hi! Started in Jan at 1.5mg and moved up to 4mg 2 months ago. So far have lost 13 pounds, which is great, but am experiencing a plateau in loss for the last month and a half despite working out regularly and eating clean. The pill definitely suppresses my appetite, so I’m a little confused why I’m plateauing. Some days I literally have to force myself to eat so I’m eating at least 1,800 calories.

Any advice? I’m hesitant to increase my dose because I don’t feel like I need more appetite suppression…