Yes bubba, I wouldn't go through all 1200 line of code either, but I would do a find for stuff like SDL_LoadSurface. Since the RAM is being eaten up so fast the code is probably loading too much stuff somehow. When you are only loading the first level from scratch its unlikely to be a problem with old stuff not being cleaned up correctly.
You mean SDL_LoadBMP(), or, if the OP is using SDL_image, IMG_Load(), right? ;)
@Mavix: if you don't have any objections to posting your code (for example, you might not want to release your game's source code), you may as well post it. It's possible that someone will look at it. Right now you're not going to get much more help.
Thats why I have decided to do it in c# instead. I have a basic understanding of c++, but for now I'l focus on c#. I'l learn c++ when I go collage, which is still quite far away.
Also, I always indent my code. I'm neorotic about it. I cant stand, or read, code that isnt indented.