Gerund vs infinitive

I have a question on the gerund and infinitival forms:-

choose the right answers for the following sentences:

1- Why don't we stop (to play/ playing) computer games and do our homework.

2- Did I tell you I was unhappy? I don't remember (to say / saying) that?

3- We have stopped (to take/ taking ) plastic bags from the supermarket. We take our own bags when we go shopping.