Breakup- advice ?

Hey y’all well as of right now I have no problems with y’all know period but I just wanted to share a little something with y’all, well my bf broke up with me about 2 weeks ago and honestly he hurted me a lot, he is now dating his best friend which she supposedly wanted us to get back together, he killed my trust, damaged my heart because I gave him more than what I could, I found this out because he didn’t change his password so I logged in and I saw all there messages which that was yesterday and about 5 hrs ago he texted me saying he missed me, but how do you miss me if you moved on sooo fast, I usually cry a lot during school, I can’t really sleep at night because all my dreams turns out to have him in it 💔 and honestly I feel like sooner or later he is gonna try to come back because I actually been in this position before but this time it got out of hand, it’s sooo much worse, and no matter what I still love him soo much but I’m confused on whether what to do, if he try to come back should I take him back? Or do y’all have any other opinions? Please don’t be rude