Amanda, your son seems to be acting like a normal 2-year-old and exercising his control. You've tried a lot of good strategies to encourage him to cooperate with nail clipping. Here are some more suggestions:
Think about how often it's really necessary to cut his nails, and try to do it as infrequently as possible. Do his nails really grow too long in one week, or can you put off the nail clipping to every 2-4 weeks?
Maybe the skin on his fingertips is very sensitive and feels uncomfortable when his nails are trimmed too closely. Try trimming his nails less close to the skin.
Maybe he has a fear of being cut by the nail clipper. Did he ever get cut by the clipper before? Instead of using a clipper, try a nail file, either a small or big one.
Does he have a favorite stuffed animal? Does the animal have claws, by chance? Talk with your son about how animals also need their nails trimmed, and now that he's a big boy he needs to help trim teddy's nails. Buy your son his own big nail file or one of the oversized nail clippers, and trim your son's nails when he trims teddy's nails—e.g., teddy's first hand, then your son's first hand, then teddy's second hand, then your son's second hand.
Keep a nail-clipping chart. You might even decorate it with photos of family members' hands and his hands after successful clippings. Give your son a star for clipping teddy's nails and another star for getting his own nails clipped. After he's accumulated a certain number of stars, give him a special reward, like a new toy.
If none of these strategies work, remember that this is probably a phase he'll outgrow soon.
Our parenting advice is given as suggestions only. We recommend you also consult your healthcare provider, and urge you to contact them immediately if your question is urgent or about a medical condition.