Hi JaJa
I hate to say it but.....Poor horse - he sounds like he has some real problems and I think some time off, a thorough vet & saddle check, reschooling right from scratch with groundwork to establish respect and some sympathy and understanding would be better for him that throwing on another harsh bit of tack to mask the underlying problem.
Sorry to come across as a bit heavy but it is an all to common story where the horse gets more and more bolshy trying to get his side of the story across from owner to owner and it's always the horse who loses out at the end of the day...usually down the road at the knackers when they are finally deemed unrideable.
Are you an experienced rider - have you worked with problem horses? Do you have the time and patience to get to the root of why he behaves this way and school him through it? Has he only done it since you bought him or did he act the same at his previous owners?
I think you need to think about how to help your horse
larri