I am soo sad ... boyfriend is losing interest in me !!!! any advice is welcomed?

my BF AND I been dating for 3 months,,,last few weeks my bf hasnt been acting the same. isaid idont want to lose you.he said idont wanna lose you either bae..so ive been thinking hes been messing around on me he calls me lateee we still sleep on the phone but thats about it we talk for a while..most of the time if iwant to txt..ihave to txt first cause he wont..then sometimes he asks why ididnt txt him today..YESTERDAY! ikept on thinking about us. isaid are you losing interest in me..he said a little..isaid why is that..he said alot of things..isaid ireally wanna kno! he never txtd bck he never called me that night.. he called me early this mornin around 9:30.. MY UNCLE SAID DONT ANSWER HIS FIRST PHONE CALL IF HE CALLS BACK THEN ANSWER IT.. DONT TEXT OR CALL HIM FIRST. AND CUT HIM SHORT LIKE WHEN HE WANTS TO GO TO SLEEP ON THE PHONE WITH ME SAY ILL CALL YOU BACK..DONT SLEEP ON THE PHONE WITH HIM..AND MY UNCLE SAID HE'LL COME RUNNIN BACK....he flirts with chicks on FB. and im gonna listen to what my uncle is sayin cuz im fed up with it..itold him about it and hes still doin it