Here is a punishment for you to perform. I assigned a similar one to another slave here, but I feel it will be appropriate for you as well, so I am only making minor modifications. You will need to do this during the day time. You will need 2 dildos and, if you have it, some rope.
Since you are such a horny slave, I'm sure you have a dildo or two available to use. You will take one of these dildos and insert it into your cunt, which I'm sure is already wet. You will then write whore, fucktoy, and slut around your pussy and your tits. Take a picture at this point with your legs spread so the dildo and writing is visible.
Put your panties back on, and tie a tight crotch rope between your pussy lips and asscrack over your panties. If you dont have any rope, give yourself a wedgie, enough so that your pussy lips are sticking out from the sides of your panties. Again, take a picture of yourself.
Now put on a short skirt and take another dildo (for your ass, so if you have an anal plug that works too) and some lube with you in your purse. Go to a coffee shop or restaurant or other public place where there are other people. Order some food / drinks and find a table that is NOT in a far off corner.
Go to the bathroom, and insert the other dildo into your ass, then retie the crotchrope/wedgie. Return to your seat, and edge yourself at your seat as many times as your Master requests. If it's up to me, at least 3. You are free to edge yourself using any method you wish...you can put your vibrating phone over your clit, or you can simply rub it under the table, or you may squeeze your thighs together. If you feel yourself about to cum, pinch your nipples hard and spread your legs until it subsides. This is a punishment, you are not to cum.
You must wait 1 minute between edges, so you have time to come down before the next edge.
Once you get home, strip, and take pictures of your soaked panties and plugged asshole and pussy. Lick your dildos clean, then send the pictures and report back here in detail about your experience.