Being a left-handed catcher is like being a right-handed first baseman. It's not going to be something that plagues you greatly, but lefties at first base are going to have the advantage is some situations. In your case, it's the righties who have the advantage.
I've been playing baseball for all my life, and Travel Ball as well. I've been on about 10 different travel ball teams, and I have seen one left handed catcher. However, that kid was a stud. His being of a lefty didn't effect him the least, and the coach let him do it. It really comes down to being the best, better than a righty. If you're as good as one, the coach will likely pick the righty.. but if you're better, he'll pick you without a doubt.
With that being said, some coaches prefer left handed catchers. Lefties do have the advantage in some cases, such as throwing down to third.
There's been countless numbers of left-handed catchers, the two that come to my head are Benny Distefano and Mike Squires.
It's nothing to be that worried over if you really love the catcher posisition. You should follow what you want to do, not follow what the coaches and other people tell you to do because of your being of a lefty. In college, you'll be able to play catcher as long as you're good enough. It doesn't matter if you are a right-handed catcher or left-handed.. it all comes down to being good enough.
With that being said, you are the judge of yourself. So you have to decide if you have the potential to be better than anyone who comes along as a catcher.
If you think you aren't good enough, I would highly advise switching to 1st base. However, if you can hit and field very good, I would say stick with catcher.
If you have elbow-problems still, I would just suggest moving to first base. I know it'll be hard.. but if you continue to have that problem in your elbow, you'll be fried by college, let alone the Big Leagues. But if your elbow is getting better by the day, stick with catching.
Hope I answered your question clearly enough. If not, let me know.