I agree with your T. I was also thinking about couple counseling to see if the both of you, as a couple, can step forward.
I understand that these are husband's issues, not yours, but since you are married and have children maybe it is worth a try?

The second reason why you should say no to your husband's request, is that if you say yes now, next request would be no computer for a year and the third get rid of the computer.

He needs to make a decision where his trust is, because if you turn off the computer you could have plenty of relationships with neighbors and other people and still he won't be a part of it.
What then? shall he close you up in the morning, going out and open up again when he comes back?

If he is insecure and has his frailties he must take care of them.
You would never be secluded enough to reassure an insecure man.