Is Heavy Bleeding During Period Sign For Menorrhagia?

4-5 month period
im 21 5'5 120lbs ive had problems woth my period after my soon was born i was 17 I've had a period for about 5 months now & its been really heavy soaking a tampon & pass in an hr or less i went to the er but all they did was draw blood & send my home i've been really dizzy & tired & missing work because of this issuer i read about menorrhagia & it sounds similar can you help? please