It sounds as if you are doing all that you can to make changes that will make a difference in your relationship. But it may not be enough.
I am currently in a very similar place in my marriage of 6 years. I have attempted to keep our marriage alive by pretending my husbands verbal abuse (along w/ other behaviors...) did not bother me, joking with him about his degrading comments (w/ humor nothing hurts, right?

), then by confronting him and demanding to get into counseling.
We have been in counseling for about six months. However, there is this huge emotional debt caused by the abuse that will always exist. The emotional pain, sadness, confusion, anger, loneliness, bitterness, hopelessness, isolation, etc... has become more prevalent than the love, trust and connectedness that once existed in our marriage.
Finally I have decided that I am completely done with our relationship.
I love him dearly and remain connected to him, but I need to protect myself.
For me, it feels as if the verbal abuse has been spiritually damaging...and I can't ever trust my husband with that sacred place again. I trusted that he would be my protector and hold me sacred...
Life is full of lessons, and sometimes they are more painful than other times.
I hold hope that in my next relationship I will remember this lesson, and not have to repeat it...I am also hopeful that my husband will learn from it as well and not subject another human to such anguish.
It seems that emotional and verbal abuse are life long lasting scars that time and self nurturing can heal.
Just my experience...Good luck with yours...