From your symptoms of fatigue and tiredness, tingling sensations and weight gain
, hypothyroidism should be ruled out. Symptoms of hypothyroidism are fatigue,depression,weight gain,cold intolerance,dry, coarse hair and skin,constipation
,muscle cramps,decreased concentration,vague aches and pains,menstrual disorders,palpitation and swelling of the legs.
I feel that you should consult a physician and get yourself and your thyroid hormone levels evaluated.