Dear Lybrate user,
your tooth was carious. Caries destroyed you tooth completely and it was become week. In this condition broken of your tooth with normal tongue pressure is a normal case. It is your own fault. When you saw, your tooth is blackish you should consult to dentist
for restoration of caries, then you could save your tooth.
* now you should consult to dentist for extraction or remaining part (root stump) of your broken tooth
. After root stump extraction you you can gate FPD.