Also, you don't have to be permanently disabled to apply or qualify for SSDI. There must be an expectation that you won't be able to work at the Significant Gainful Activity level for 12 months (SGA is $1170 per month in 2017.) Substantial Gainful Activity

You can and should list your Alleged Onset Date as the month after you last made SGA. That would be 2 years ago, but you can only receive benefits 12 months prior to your AOD.

CRPS does not have it's own Listing which can make it unlikely to be approved unless you follow through with the process and go to a hearing. (Some are approved by meeting another Listing. If they require the use of a walker or wheelchair for example.) An Administrative Law Judge (ALJ) hearing will take 2-3 years after applying. So even if you expect to be denied if you apply now, starting the process is not a bad idea. If you wait to apply until your docs agree you can't return to work, don't assume you'll be approved quickly (6 months). So unless you have family or resources that can potentially support you for years while waiting for a SSDI claim to be approved, not filing can be a risky proposition.

Also, remember your Date Last Insured (DLI) is a factor. Check with SS. If you worked consistently, the maximum time would be a little more than 5 years from when you stopped working.

And lastly, even if you can return to work, you can receive an SSDI Closed Period Award for the period you were unable to work due to disability.