You shouldn't be using house hold items to mastrubate
Invest in a vibrator or silicone dildo , go on amazon they have a lot of sex toys just search dildo or vibrator, under health and personal care. There not really expensive.
Always clean anything you use with antibacterial soap and warm water
Before and after use.
And if your horny tell your boyfriend to come FUUK you
And probably because the brush hand is smaller than your boyfriends d!ck you might have poked or accidentally scratched something. And like the previous answers try using water based lube, but with a real sex toy.
Don't worry just don't do it again , but if its like bad bleeding than see a doctor