Anxiety vs Phobia

So after six months of watching my friend pass out after a dinner and develop that fear, I think I've come to question whether I have anxiety or a phobia. All my life, I've had phobias that go away once another shows up (I'm not sure if this is normal, but here is the order):
My first one came around when I was four or five and lasted a couple of years- the fear of the toilet overflowing (seemingly a natural fear a toddler, but it just lasted so long). Then in Third grade, I was afraid of my teeth falling out AND, at the same time, a wasp stinging me. I would avoid eating to not lose teeth for about a year. I would only eat dinner or snacks. Around fifth grade I was TERRIFIED of head lice. To this day, though not afraid of it much anymore, I still have the habit of covering my mouth when I sleep (I was afraid of ingesting them or something???). In sixth grade I was afraid of mice. At the time, we had a mouse in the pantry and my parents refused to kill him off (either that or they couldn't catch him), so I was afraid of him climbing into my bed at night. Of course, after that, it was fireworks. I find this one the funniest, actually, as it lasted a whole three years, but I would only have to be afraid of days such as New Years and Fourth of July. I was DEADLY afraid of the ashes coming down and lighting me on fire. I would stay inside or under the cover of the garage on those days. I then became afraid of throwing up (this one was pretty bad) and I went to school, but every morning I would bring plastic bags because I was afraid of throwing up. I learned that this fear is common, but it still took over my mornings. Around mid-morning it would go away, but I worried myself sick for two years. Through all this, I developed a fear of tornadoes, and though this one doesn't go away, it doesn't bother me like the other ones do. Finally, we come to this one that is absolutely controlling my life: passing out. I came to the conclusion that it's a phobia because though I use all of the coping skills I've obtained and I went out everyday to practice being out in public (exposure), I still cannot tell myself that I'm okay. I tried to go on medicine, I think Lexapro, but one of the side effects was passing out if you didn't intake enough sodium. I know side effects are rare, but I couldn't even breathe knowing this thing was in my body, and I want to go on medicine, but I don't know what a good starter is (that doesn't have this extreme of a side effect). Knowing all this, I'm stuck, have a flight to California(by myself) in two or three weeks, and can't even go to the store by myself. Thanks in advanced for any help!