I want to break up with my boyfriend but I don't know how

[sour candy]

Well if I were you, I'd make a plan to have other living arrangements set before you break up with him so that you aren't going to be living in the same space as him for long after the break up. 
I was having serious relationship issues earlier this year and we went on a 1-2 week "break" (still exclusive obviously but giving eachother space and not acting romantic towards eachother so I could think about my feelings and what I truly wanted). We ended up stronger than ever after the break but if you don't believe that working it out is an option, you just need to be honest with him and rip the bandaid off