hi welcome to HCM
-i had gone through your query and understand your concerns.
-basing on your history and presenting complaints,i would come up two possibilities,
1.first one ANAEMIA
;may be the cause for your sufferings.
check your Hb% levels may confirm the diagnosis
2.second possibility is,THYROID PROBLEM;iam unable tell exactly whether it is hypothyroidism
for thyroid profile,
scanning for thyroid gland may confirm the diagnosis
please rule out the another possibility of cardiac dyspnoea with ECG,and ECHO
wishing you good health