Haven’t been eating and sleeping much the last 3.5 weeks but gained 4kg?! HELP

As the title said

I broke up a month ago and haven’t been sleeping or eating much. Occasionally I could eat normally when I’m with friends but I don’t drink alcohol
I do eat sweets when I’m very tired and triggered, but it’s not much - also considering I only eat 1-2 meals a day, the calories wouldn’t even exceed my TDEE

I maintained my daily walk (so I don’t cry too much) but haven’t gym at all

I don’t understand. It’s stressing me out on top of my job hunting and breakup.

Also, I’ve been reliant on melatonin and occasionally temazepam to sleep at night but still got woken up a few times in the middle of the night with anxiety.

Oh I also have PCOS/ PMOS