Sequence Diagram Assistance with external database

I have 5 Java/android classes which are in sequential order. The user inputs data into the text box and clicks next. Two things happen, 1 the data the user inputs is passed to the next activity and it is also inserted into an external database.

The same things happens on each of the 5 activities. I’m struggling to represent this in a sequence diagram form. All the sequence diagram examples I see dont have an external database involved in every class/activity and my diagram only moves forward, most diagrams have methods moving back and forth.