Help- I do t want to loose my best friend

So I've been with my man for 6 years. My daughter was 18 months when we got together and calls him dad. Matter of fact if her bio dad were to be sitting next to her she would not know it was him.

Fast forward my bf and I conceived our son and he is now 15 months old.

During our relationship together we have had several ups and a few bad downs.

At this point he is wanting to break up to presume his own endeavors. He has also send dick pics and I've caught him a few times.

And to top things off he and I don't have s x but once in a blue moon.

Of course there are so many details being left out but ultimately I want to know if you can ever gain trust again after your heart has been ripped apart?

Also would like to know if there are so so so many great moments in our relationship can we bounce back from all this selfishness?