Sorry to read of your situation. FWIW, I would not class this in the same league one bit, and it's not like you've gone off and been in bed with someone else.
Of course cyber fun is not a real solution, and it will do only harm to even mention it, so turn the diary onto the next page and put it behind you as something which should not have happened, and throw the memory into the depths {you may want to pull it out for a reason not to do the same again or in place of doing it again... set aside guilt for the moment, as your situation is damn hard, and you were desperate, and you know nothing further will happen on that front as you have a family you love).
Reading about your situation makes me wonder how many other couples are in a similar state (with redundancies and so on), and dear god you are more than "pulling your weight" when it comes to running home, family and being breadwinner too.
I hope that a few who made initial judgements can drop their condemnation down a few levels, given what you're up against at the moment.
Clearly some of the other ladies have "been there", and there may be others who did something similar but just haven't come across this thread.
Hope things can improve for you {all}.