So, if I'm understanding correctly, your problem is low blood pressure (hypotension) and not elevated blood pressure (hypertension)--or, more accurately, you have sudden drops in your BP that cause you to faint? Have I got that right? And your new medication is supposed to keep your blood pressure elevated?
It sounds like they were pretty thorough in ruling out any other problems.
I certainly hope the medication does what it's supposed to do, so you don't have any more blackouts and falls. How is the gash on your head doing? Has it healed?
Did they suggest you do anything else to help prevent the blackouts, in terms of diet or lifestyle, or do they think the medication will be enough?
What an unexpected detour into the hospital world you just took. You captured it quite vividly with your narrative. I'm glad you gave us a "spoiler" so we knew the outcome would be good, because the suspense was getting nerve-wracking.
Stay well. I hope the medication will resolve the problem.