gained 18lbs in 2 months on levo despite lifestyle changes, labs normal. help?

can someone pls help me?? i've been taking 50 mcg levo for two months now, and since then i have put on an exceedingly high amount of weight despite changing my diet and exercise (coinciding with the start of levo). i've been in a severe calorie deficit with mostly protein, weights 3x/week, average of 8k steps/day. i know some of it is muscle, but a lot of it is fat and water weight, which should be impossible.

i went to my endo bc i thought it was bc of the levo (i had previously gained weight on NPT as well), and i just got my labs back.

TSH 2.89

free T4 1.19

free T3 330

cortisol 19.9

i feel so so so lost and discouraged. i'm 4'11, so every pound i put on shows far more than the average person. i've also, for the first time, been exceedingly diligent about my diet and exercise for a prolonged period, and that i'm basically blowing up unrestrained is immensely frustrating. i've tried glp-1 in the past and i hated it, and in the past, even without a glp-1, i didn't particularly struggle to lose weight.

please, someone lmk where to go from here. i'm going insane.