I know it is hard. This is a very difficult process. I am glad you still have some part of you that wants to continue. Many many people who are very very ill get turned down at this stage - it means nothing about you or your condition.
You are doing a great job of learning more and taking good steps on your case. that is very positive. In my experience, the people who really make an effort like you are do get approved in the end.
Many people find that having a lawyer is very helpful for a hearing appeal (that comes after reconsideration).
I have not really heard stories of lawyers doing very much to help reconsiderations, but you can try. Just because I have not heard of it, doesn't mean it doesn't happen
Whatever you do, just make sure to make the reconsideration deadline - must be in their hands within 60 days.
You can request a copy of your case file on CD, that will show you exactly what records are in your file and may also give you more information on how they made their decision.
If they did not use your rheumatologist report, then you can mention this on your request for reconsideration. It gives you a place to write the reason for your request and you can write that an important document was left off the list of medical evidence and then send it to them again along with the rfc forms if they are not already there.
Are you currently working at all? Do you currently see a doctor?