My bf is cheating on me

So one night me and my best friend were up and I was like txt my bf on kik and see what he replies (he dosnt know her at all) and she asked him if he had a bf and he said no I don't and now we don't know how many other girls he is txting I love him so much and every time I txt him he Is just like I am busy. And he lives in London so the time kills us but we have been getting through it but what should I do rn we are just playing it through with the whole bf and gf thing but I am pissed that he is cheating and we don't even now how many other girls he is txting here are some of the txts mine are the aqua with my bf and Diana's are the purple with my bf