Hi thanks for your question
Your are having lump in axillary region that is under your armpit(side left or right not mentioned).
You noticed it two days 2 days ago.
You have tiredness
and exhaustion from last three years.
The lump which you have mentioned in armpit, are axillary lymph
nodes, which are enlarged in infection or malignancy in chest of same side.
Since your axillary lymph node enlargement is associated with tiredness and exhaustion, your advised to consult some physician, who will investigate the cause of enlarged lymph nodes
you may need FNAC(fine needle aspiration cytology) of this mass.
Hope I answered your question.