Re: help me please
I agree, you do not have to agree to finance this. Tell him no, and that you are not going to discuss it anymore.
As for losing him, where else would he go? You'd be more likely to lose him if you financed his trip.
I know he's your son, but if you're scared he might hurt you if he gets in a temper you might have to consider having him move out. You need to consider yourself in this too.