My boyfriend has been dry since we started going out and I can t stop crying?

I m 16 goin on 17 and me and this boy have been talking for months and he always told me he loved me and I m the best girl he s ever met and all that and we would talk non stop then when we started going out he hardly talks to me and patches me . We have been going out for about a week now and I have a asked him

If I had done something to upset him like if that s why he wasn t talking and he said no I haven t done anything but I keep thinking to myself why would someone be as dry as this if I haven t done anything and last week he asked me for a video of me slapping my *** and I said no but today I changed my mind and said yes I will and he was like nah , after begging and everything . I know he can t save it because I go on his phone all the time and that and it s on snapcht so I would know if he screenshot and I have sent him stuff before but he didn t save them I checked , why is he being so dry I have said to him about 6 times why u patching and he never answers bit opened them , help please I can t stop crying