Need help with my horse!?

I have a 6 year old gelding who i have had for awhile now, when i first got him he was quite now he has gotten quite hot. I sent him to a trainer for a little but all that did was make our bond less.. I need to try to get a bond with him so i can connect with him but at some points working with him scares me. He has a good buck to him and when i try to lunge him he turns into me and trys to buck i feel when i fight with him it only makes matters worse. I need advice and help.