I think your condition could be 'spurious pregnancy'. Means a condition in which some signs and symptoms of pregnancy present in a woman who is not pregnant in reality.
it can occur in women who are having strong desire to become pregnant or
in women who are having intense fear of becoming pregnant.
I think you belong to second category. Your feel of being pregnant and tiredness
are because of this condition only.
You take help of your family members in facing this problem. You consult gynecologist by ultrasound
examination she can demonstrate that you are not pregnant, if needed you can take the help of psychiatrist