Strip naked, put a vibrator in both your ass and your pussy, and rig up a crotch rope to keep them both in nice and tight. don't turn them on just yet. Then gag yourself with a dirty pair of panties. If you have a bedframe with bars(
I'm thinking something like this, if not find something suitable, go in front of it with your ropes, and squat facing in front of it, and tie your knees to the bottom bar, as far spread as you can get them, do the same with your upper thighs. Now turn both of the vibrators on high, then set a timer for 45 minutes, then tie your hands to the top of the frame, make sure you can get out of them.
When your time is done, untie yourself, and then for every time you came, slap your pussy 10 times. After this, snap yourself on each inner thigh twice for each time you came with a rubber band. After you finish this, you may remove the vibrators, if you cum while you are slapping, snapping yourself, you must repeat the punishment after the first round.