I am unable to care for my wife due to a back injury and her Quick appearing on set of Dementia in placing her in a home where she can get care I feel bad going to see her in that state and feel equally bad leaving her there to go home.
My guilt level is so high i enjoy less and less each day
I hear a mixture of anticipatory grief and some depression in your words. Please find someone that you can talk about all of this with face to face. Do something nice for yourself. Feel free to keep on venting here and let us know how things are going.
I understand why you feel guilty and I know by saying "don't feel guilty" won't automatically change how you feel but do try to be kind to yourself. Again, you've done the right thing.
Feeding guilty seems to be an integral part of caregiving. If you kept your wife home you would feel guilty that you couldn't give her proper care. If you place your wife in a care center you feel guilty that she isn't at home with you. I'm not sure we can ever fully eliminate the guilt feelings, but it is important to push them into the background and not let them influence our decisions. Focus on doing what is best for your wife, not on what will help you feel less guilty. And it really sounds like you have done the right thing for her.
I never promised my husband that I wouldn't place him in a care center. I did promise him, repeatedly and sincerely, that I would never abandon him. For better and for worse, in sickness as in health, I would always be there for him, I would advocate for him, I would do my best to ensure he was getting the best possible care.
It is hard for you to visit her. I understand that. But it is part of doing your best for her, part of not abandoning her.
While you are ensuring that your dear wife is getting the best care, apply that duty to yourself, too. I think it would be an excellent idea to see a counselor. Don't wait until the depression gets totally unmanageable. Seek treatment now. Depression is treatable. Please see about getting some treatment! (That will help you be more realistic about your guilt feelings, too.)