I have several ideas you could use but a fave that leaves you free to do whatever while you suffer is this.
Get some large bandaids, the regular size work but bigger is better here. Next spread toothpaste on the pads on three of these and apply one over each nipple and one over your clit. Now put on your bra and panties and any other clothing you like and enjoy the ride.
If you're further along the maso spectrum and want something more hardcore try using icyhot or similar in place of the toothpaste.
Enjoy!