I think I hv low BP cause whenever I stand up from lying down, I feel dizzy & my vision is blurred. I feel like fainting & almost puked. Wht do u think?

See a physician. There are many reasons for low blood pressure. This type of problem need immediate medical attention. You may be dehydrated for some reason, etc,etc. Impossible to know without examining you. Get yourself to a physician today, or to Emergency Room or urgent care center. Better to be safe than sorry.
Postural Hypotension. Or low blood pressure upon standing is a common finding in people, even young people, on prolonged bed rest. Getting up very slowly in stages helps. Sitting up in bed for several minutes, then sitting with feet off the bed for several minutes while moving the legs, then standing with assistance while moving up and down on the legs. Hydration and sitting rather than lying in bed will help.