Oh sweetie! I am so sorry about your mom's diagnosis. My grandmother had dementia for 4-6 years before she died and she became so nasty toward almost everyone, except my S3 after he was born.
I know you do not want to consider a nursing home, but I can tell you, from experience, if things are not great between you that it will wear on you and tear you down mentally and physically. I watched it happen to my own mother. She put her entire life on hold in an effort to please my grandmother and nothing ever made the woman happy, no matter what my mom did for her.
Really think through your decision and at least look into some care facilities. Even see if some have daycare like programs, where you might be able to take mom so that you can get a break if you decide to keep her at home. Do a ton of reading on the diagnosis. Be as informed as possible.
As for H, i would leave him hanging in the breeze right now. If he cannot be behind you 100% to support you, you cannot allow him to further drag you down.
We love you, honey hang in there. IF you need a friend to talk to on the phone, feel free to email me in the alt and i will send you my info.
Living God's blessings with grace and dignity~ SMW
M40/H36 T16/M14 4K B2/08 S4/08 current
Love never gives up, never loses faith, is always hopeful, and endures through every circumstance. I Corinthians 13:7