Sorry to hear this happened to you. It's tough getting over the intimidation you feel after an incident like this.
I carry a pepper spray canister on my keychain, have thought about carrying it on the bike, if only for the occasional rowdy dog. It is a mixture of mace, pepper and fluorescent spray paint. Can be had at any gun shop. One thing to remember, you don't want to let them know you have it, just use it if need be. In other words, it doesn't work on intimidation factor like a gun does. I've never had to use it, but have been glad to have at least some form of defense with me.