The "Catfish" star tells TMZ ... he's on the mend after he was hit by a truck while riding his e-bike in Long Island, NY ... revealing he's set to get an X-ray next week to see if his spine has fully healed. If so, Nev will be allowed to take off his neck brace ... which is necessary if he wants to start training for a marathon sooner rather than later.

While Nev admits he still has a lot of nerve pain and discomfort in his hands and arms ... he's determined to complete 26.2 miles in the near future.

In fact, rather than run the Honolulu Marathon in December, which was his original plan, Nev is now planning to participate in the NYC Marathon in November.

Per Nev, a good friend -- an athlete who happens to be blind -- reached out to him and asked him to run as his guide for the road race. His friend is already super understanding about his situation ... noting they'll take their time -- even if it means jogging slowly or walking.

As Nev put it ... his goal is simply to complete the marathon -- especially since this whole experience has taught him that you shouldn't waste time.

He credits his wife, Laura Perlongo, for getting him through this ordeal.

Despite the extreme nature of his accident, Nev tells us his e-bike is still intact ... currently waiting for him at his dad's house.

Surprisingly, Nev isn't deterred from riding an e-bike again ... but he plans to take more safety precautions in the future.