My boyfriend is behaving weirdly... :(?

i meet him while travelling in train v started talkin den started flirtin v xchngd nos d next day he msged me n den we strtd talking on cel itslf v met once den he said dat next day mornin he is goin london for vaccation n after comin he is behavn badly v juz hd 1 cht which he ended up widout replying? please help, wot shld i do now?