You've mentioned before about the emotional issues in your marriage, not to mention the normal stresses of caring for small children and having job/money worries. Methinks that's where your libido ran off to. If intercourse is painful despite using lubricant, then I wonder if you're having some vaginismus (tightening of the pelvic and vaginal muscles reflexively due to anxiety and stress).
I know this may sound nuts, but, have you tried alcohol, as in, getting drunk? Maybe just once every couple of weeks to make DH happy?
I have ZERO interest in sex unless I'm on testosterone and estrogen, but since I have no emotional issues in my marriage (none to speak of, really), I can kind of "just lay there" whenever I have to in order to keep the peace. But that's not an option for you and no, absolutely, you must NOT continue with sex and ignore the pain, especially with feeling it's akin to being raped, because that will only worsen the vaginismus (if that's what you have, and it kind of sounds like it).
I don't know much about this condition, only that it is thought to have either physical or emotional causes, or in some cases, both. I knew a woman who had primary vaginismus though she didn't think it was emotion related, and she had to use a regular regimen of dilators for months before she could have sex with her new husband. You might ask your gyn about this. It's a serious problem. Wishing you resolution somehow.