Should I get a new vehicle?

I have a 1999 Dodge Ram 1500 and LOVE IT! It's been great up until this year. Now everything is breaking down: Had to get a new battery, new engine, the transmission is malfunctioning, four new tires. I have the money to buy a new GMC Terrain but I'd rather keep my truck. I haven't bought the engine yet but it'll be $2100. Should I trade it in for $4,500 after I buy the 2100 engine? Or fix everything and keep it?