What are my EB-5 options after my I-829 was denied after pending for years?

If the I-829 is denied, you can renew the application in removal proceedings. But getting a hearing is another matter because they are not ordinarily issuing NTAs. So you can try and file a motion to reopen, but without compelling evidence, that will not succeed. You are a permanent resident until the Judge orders you removed and technically entitled to temporary stamps, but if you travel abroad, CBP may issue an NTA when you try to reenter. Cancellation may be an option if you have sufficient accrued time before the NTA is issued.

It is important that you contact immigration counsel immediately.

Sorry to hear about the I-829 denial. NTAs are delayed across the country and particularly in large metropolitan areas. You will receive it, eventually, and its timing is not a reflection of your case. My advice to you is to get an immigration attorney immediately - possibly two; you need counsel to represent you in immigration court and you need an EB-5 attorney to advise on the possibility of I-829 renewal. Some attorneys represent clients in court and understand EB-5 but those are few and far in between (I personally partner with a removal attorney for these cases). The removal attorney can advise you regarding cancellation. Good luck!