Katie,
I have mctd and have been on SS disability for 3 years. It took 3 applications and a lawyer to finally get it approved. The standard is that you are completely disabled and expect to be for a year or more. My case was extreme and life threatening: I was a quadriplegic and could not swallow when I first applied and got turned down with the comments that I would be OK. The second application was not much different and they decided I could do something I never did to earn a living....strange. I think they hire Moe, Larry and Curly as doctors to review cases.
Hired an excellent attorney the third time and had approval within 3 weeks and did not have to appear before the administrative law judge. He just looked at my case and said you qualify.
The whole process is one of denial not approval and if you fill out the forms incorrectly or your doctor's letter is not worded just right you will be turned down. That is where an experienced disability attorney can help so that you don't shoot yourself in the foot.
If you are capable of some work you probably won't get approval. After 55 the standards are lower but it is still difficult and some states have backlogs of several years to appear before an ALJ. Totally unfair.
Good luck but don't try to do it yourself. Attornies take the cases on contingency and the initial interview will be a good indication whether you really qualify or not. Attornies will not take cases they think are not winnable.
Bill