I’ve been wearing braces.

That's fine but I think most people would say "I wear braces." or "I have to wear braces."

I’m happy that my teeth are becoming straighteneding up, but it is uncomfortable when eating.

A pPieces of rice and ramen noodles often get stuck behind my braces.

Since you're talking about something that often happens it's better to use the plural for both types of food.

Melty cheese isn’t alsoalso isn't good because it sticks behind them and it was hard to get the cheese out.

After I had eaten a croissant, it covered most of my brackets were covered with it.

I learned that I should eat curry the day before the day when exchanging my braces because mythe rubber attachinged to the ceramic brackets turn to yellows from a clear color to yellow.

I encounter a lot of difficulties during wearing braces, but I’m looking forward to the day when I come off my bracesan have them taken off.