hi sir/mam,let me make 1 thing clear that even with severe Hashimoto causing hypothyroidism,weight gain is at the maximum of 5 to 6kg. of course I do accept that 5-6 kg can also be distressing.i assure you that it is reversible completely just by few modifications in your life style.
1)first and foremost is regular exercise(brisk walk,aerobics,yoga etc) for at least 45min/day and 5 days a week.it would not only help reduce your weight but also alters the sluggish body and mind attitude which come due to hypothyroidism.
2)dietary modifications like consumption of very low carbohydrates,moderate proteins and low fats,high fibre,much of fruits and veggies,less of refined and preserved foods helps reduce weight.
3)I can understand that you are very compliant with medication,still get your thyroid profile done to just check if it’s under control.
one more suggestion is please do not compare your health condition with that of others as every aspect like symptoms,diagnosis,comorbidities,treatment,how individual responds to that may differ.the above measures would definitely help you reduce weight.hope my answer is clear.any other health issues,please do bring to my notice.thank you.take care.bye.