Therapy Will Help You Overcome Your Shame
You aren't feeling guilt, you are feeling shame. The best solution is go to therapy and learn to unleash this shame feeling. I've just made a breakthrough with my therapist.
I've lost all sense of codependency now. I do not feel guilty for moving out on my 70 year old mom who pretends she's 90.
I will feel no guilt by putting her in a nursing home because frankly, it is the most healthy environment for both of us. With therapy you can begin to see the situation for what it is.
You are PERFECTLY JUSTIFIED in feeling it's time to move on from this. You are RIGHT to feel put out, if you are put out. I personally wouldn't want your situation and think you should not feel ashamed to move her into a place where she can have her needs met and not make you crazy.
You are responsible for your own happiness. You owe yourself to have a good life, you don't owe it to her to have a bad life to make her somewhat okay.