Lack of sleep. Abt this kind of feeling.

Hi i recently had a baby a month ago n ever since been hvng less sleep n a ver very irregular sleep pattern. I am unable to sleep when she sleeps n she keeps me up through the night rite till abt 5am or so n even after that disturbed sleep till 8am which is barely 3hrs... My baby doesn't sleep after her bath till about 2 or 3pm in the afternoon ... By then I'm exhausted... After she sleeps in the afternoon I get sleep till about 7pm which maybe abt 4hrz of good sleep... Of late i am feeling a heavy feeling in my chest n upper back but it goes after my sleep comes back an hour or so after I wake up ... Is this a sign of heart issues or just lack of sleep causing it... Been worried abt this kind of feeling.