I think to truly get over B you have to quit messaging with him (not focus on him) and do something else with someone else. If you want your love to work with your current honey, you need to think about him. We can only focus on one thing at a time so pick something/someone else to think about and B "has to" go into the background along with your primary school teachers, etc. (in kindergarten and 1st grade in the US, we sometimes hug our teachers :-)