The two of you didn’t date, grow into love, and then decide to have a future together. Instead, you kind of slid into living together – without talking about what it meant to each of you. At Christmas, he acted out his ambivalence about whether he is really ready to be in a committed relationship and cheated. This was neither mature nor caring. A question at this point is whether he is with you because he found out that he really does love you or if he got scared about the idea of putting himself back into the dating scene and is back to you because you are familiar.
Meanwhile, you seem to be in the relationship primarily because you don’t know what else to do and don’t see options for yourself. In addition, you have grown up observing your mother put up with cheating and addiction. In a sad way, you too may be opting for the familiar instead of putting yourself out there to find someone who you can love whole-heartedly. Unless you do some solid personal work, you could end up living some version of your mother’s life.
Although you and your boyfriend have been good friends for each other, neither of you seems to be ready to make the unconditional, loving commitment that living together and making a life requires.
Please consider taking a big step back. There are worse things than going back to live with your mom for awhile (like spending the next 10 years with the wrong person). If you can’t find work, it may be because you don’t have the education or experience you need. If that’s the case, figure out what to do about it. Get some schooling or do some volunteer work or an internship to make yourself more marketable. You might check back with counselors at your old high school to get some ideas.
Canada is a big place. There are good schools and good opportunities throughout the country. You don’t need to be stuck in a shaky relationship to make your way in the world. As you said, you need to figure yourself out.
I wish you well.