Yes, definitely, but by dieting further you exacerbate the situtation - it's a lose lose scenario and it sucks. Research estimates the hypoT can diminish BMR by as much as 25%, which would bring your TDEE calories down as well (more than 25% IMHO because when you're that tired you just can't do much, so your Total Daily Energy Expenditure really doesn't go up much). It's pretty much impossible to actively lose FAT while dieting and being untreated/medicated for your hypothyroidism - and the worst part is trying to can actually make it worse.

Nat