Many on here will understand your feeling of loneliness
@Avis - and I am glad that you have found this forum. It will definitely help.
I remember feeling isolated on many occasions myself. For several years we got out and about to socialise quite a lot - but as the disease progressed, the more my husband and I became confined to our own home - and it was not always a home my husband recognised (though fortunately he was generally accepting of it because I was here with him).
I was also lucky that, even though there were many hours of little interaction during the day while he slept more and more, I did know that our son and daughter would eventually be back home overnight. Just knowing someone else was in the house was reassuring in itself, even if they were also asleep!
I can only imagine how much more isolated I would have felt had I been totally on my own with the situation. Even so, being able to come on here in those quiet hours and talk to people who understood the complexities involved with dementia, as well as the challenges of caring for someone with dementia, was what helped keep me going through the darkest times.
Keep posting, there is always someone around who has gone through similar or will be going through it with you - and just knowing that in itself, often helps lessen the feeling of loneliness