I have been through what you are describing. My husband has had PPMS since 2001, he is now completely dependant on me, I gave up my work a year ago to take on his care full time.
You need to get an assessment done, this will then hopefully enable you get some assistance. We used to have carers twice a day, morning to get my husband up and dressed and lunchtime to make sure he was clean etc and then I did the rest. Now I do it 24/7 except for 14 hours a week when they sit with my husband while I take our daughter to clubs etc, this enables me to have a 4hr break once a week which doesn’t sound a lot buy does enable me to have some down time. He OT or adult social care should be able to help you.
I found caring for my husband very difficult for a while, like you I love him dearly but I did question it at one point and considered leaving but couldn’t because although I was questioning if I loved him enough, I couldn’t leave and I am glad I didn’t. I was finding it difficult to deal with the changes in our life but I know he was struggling as well which is why he was angry and said some horrible things. Perhaps you can get some help for both of you to help you with the adjustments mentally and perhaps find a local group to go to so that you can talk to people in the same situation. I know we have a local meeting once a month for carers, I have never attended but have thought about it but we did use to attend a MS coffee morning once a month as a couple. This enabled my husband to talk to other MS suffers and me to understand that some things are common in MS suffers ie mood swings, depression etc.
Unfortunately being a carer can make you feel isolated and lonely but I am sure deep down your wife appreciates all you do for her.
Take care and please talk to someone, they can help.