Help me im sick

So im currently 29yrs in my 3 pregnancy. My oldest is 9. The following child is 2. But when i tell you i can't get a day without being sick. 24/7 im throwing up. Got a script for promethazine tabs but an the work but im convinced that they are possibly to strong because they make me high from them an they make my stomach turn. Ive tried everthing i can think of with no luck. Ive thrown up on n off for the last 1.5days.. Doctors say im ok. Any advice is welcome. Please help