My ex-girlfriend and I might be getting back together, but I don't know if it's a good idea..?

Okay in your situation you just need to chill and quit calling and texting. She already knows how you feel. The ball is in her court. As much as it hurts you need to sit back and wait for her to contact you. You can't force someone to feel the same way about you as you feel about them. Just chill and if it's meant to be she'll contact you.