Breakup

Not long ago, my boyfriend broke up with me, after 4 years of relationship. For first week i felt so sick ,lonely and betreyed.... It all started like 6 months ago, then i said to him that i don't like that he smokes weed, and it truly made him super angry ( from smoking weed often) he would get mad at me super quicly, he broke up with me 3 times before but just for a day, and he would come back crying and saying that he's dumb and he can't live without me, but more than a week ago, he said that he wanted to end our relationship, bc he doesn't want to live together, he wants to live alone ( he already does live alone and we would meet few times a week in the evening, sometimes 1-2) he said that i pressured him too much about living together but i literally would mention him that "" im so excited to live together". So his desicion was out of the blue. A month ago he told me that he cant live without me, and he would have brought a ring if i wasn't let him back to my life. And now, he's just breaking up???? Although he said prior that he loved me and missed me. This pisses me off the most. If you dont feel it anymore , why eoulg yousay it ??