Suggest Treatment For Sudden Onset Of Memory Loss Followed By Blackouts

So I ve been blacking out for about a year. They ve all been from standing up too fast, and sometimes when everything goes dark, my legs start shaking but I can t control my body, and I m concious the whole time. The main problem that I m concerned with is that every time I black out, my memory of anything since I was a little kid is completely wiped out, and it s getting really bad. It s hard for me to go through high school like this when I remember almost nothing in every situation that I go through, or I won t even remember that event. I could really use some answers, because I don t want to live not being able to remember almost everything in my life.