Piggy skin is very sensitive and if you are trying to use the clippers with the plastic guards on so they don't cut too short you might have the same problem as me - my poor girl leapt and jumped as her skin was touched but we managed it without them. Someone else has asked about this recently too:
Louise used to look like this - she couldn't see!
These are what I used...
about £12 off Amazon. I just searched for quiet pet hair clippers and these rechargeable ones came as a set with some scissors and the plastic guards which mean you can't cut too short. But she hates the plastic guards as they have to press against the skin and comb through the hair so we just had to lift a clump of hair, guess at the length, zip it through without touching the skin and hope she forgave me!
Human hair clippers are often mains operated and vibrate quite ferociously but little battery ones are quieter. She looked like this after:
View attachment 186183 As
@Swissgreys has said you don't have to do it all at once. When I did Louise I didn't touch the skin at all - just waved the clippers into the fluff. She gets very distressed about being brushed or combed so I made the decision early on to not put her though this and just keep her short. It lasts about 6 weeks. If you have the money I think vets or vet nurses will do it for you in some places but I don't know how much they charge. Good luck poor tangled piggy x