Should I forgive him first?

Im 18 and have been bumping heads with my older brother that is 21 for the last couple of years now. He always tells me how bitter I am and how I always think im tough when in reality I am nice to everyone I meet, I hold doors for strangers and I am sometimes in my own world. He makes it look like im the bad guy always. Last fight he was threatening me on how he was gonna knock me out and coming at me while I listened to him talk. In this argument in the middle of his anger he offered me a hand to call a truce but I was so angry and wasn't ready for an apology that i ignored it. Right after that he started to shove me and pushed me over the weight bench pushed me face and and gave me 3 cuts and a bloody nose. Afterward I walked away and grabbed a knife. I ran to a field and was about to kill myself over runned by tears and regret. Note that I was trying to do right by god and he just ruined it for me, I moved passed my old ways. I sat in the cold for an hour and went back home. Went to sleep and here I am today. I know god says forgive. I forgave in my heart but not in person because I always end up apologizing. Will god understand?