If your primary care doctor is the one you're seeing for this, it's time to hit them upside the head with "this is not ok". For your long term health, you need to be able to be active. Be very specific that the birth control pills they've prescribed cause more problems than they solve, and that the bleeding is excessive.

While you're waiting to see a specialist, it can't hurt to do things like increase the red meat and dark green leafy veggies in your diet. Cooking in cast iron also gives trace iron. Also, find something you like to drink and drink it. If hot tea makes you happy, drink hot tea. If lemonade makes you happy, drink lemonade. Plain water provides good hydration, but so does pretty much anything that contains water. Alcoholic drinks do take quite a lot of water to metabolize, so don't count them. Otherwise, just drink things. 2 quarts of liquid is a nice reasonable minimum in a temperate climate. You may want to shoot for 3 or more, so your body has extra fluid to help with the blood loss.

Dietary support won't fix things, but it may make it easier to stay out of the hospital while you wait to see a specialist.