I want to married my girlfriend but she is in Colombia. I'm disabled but honestly I never found some one that cares more about me. What should I do?

You need to physically meet her within 2 years of filing a fiance visa case. There are very few exceptions. The meeting place can be in the US, Columbia or another country. Once you physically meet her, then you can file for her fiance visa or a spousal visa if you get married at the time you both meet.