It will never be too easy to end up a relationship knowing that you have a lots of memories together. But then, if you feel that you are not happy anymore and your relationship is unhealthy then that is a huge tip for you to break up to him.
Second, figure out what exactly you’re going to say to your boyfriend. Obviously, the first thing that he will going to ask you is “why are you doing this?”. So, tell him honestly what are the reasons why you are breaking up with him, don’t over exaggerate your reasons. Tell him in a simple way like “I no longer have feelings for you”, “I think, we are not for each other anymore” as easy as that. But remember that this conversation is going to be painful for him and for you. Be honest and sympathetic, don’t be angry, just say enough so that you can explain the reasons why you are breaking up with him.
When it’s over, it’s over. After the break up tell you’re ex-boyfriend now that you won’t be contacting him for a little bit, ask him that respect your decision and your decision is final. If you have his things and he has your things make sure to stuff exchange belongings. But also remember that that’s it period, no talks and see him in public places or bring a friend so that you can easily get rid after exchanging