I did it - I moved in with my 87 year old Dad and lived away from my husband (we live in Ireland, Dad was in the UK) - initially to help Dad recover from a hip replacement, but then he had a fall, had a leg amputated, was diagnosed with dementia and prostate cancer - and I ended up living there full time - eventually not being able to go out at all (for the last 2 years of Dad's life, he died when he was 91), because Dad couldn't be left alone. This was with a 4 x a day carer regime - he needed two people to operate a hoist to move him for toileting and to prevent pressure sores etc.
If I had known - going in to this - how things would progress, then I personally would still have chosen to be there - but that doesn't mean it would be the right decision for you - and I'm telling you this because I just want you to be aware of how the situation could develop, and what a profound effect it could have on your life.
There is/was no respite care available - I was more or less left to get on with it. There was no consideration of my mental health (luckily I'm fairly resilient) nor physical health (I got an exercise bike as I couldn't leave Dad's flat without arranging for a 'dadsitter' - far and few between). You start to feel totally insignificant, and it's difficult not to begin to resent your loved one for the position you find yourself in. It wasn't Dad's fault though, and I managed to keep that at the front of my mind throughout - which was a struggle at times, in all honesty.
Your future may differ from my past, of course - but don't go into this thinking that there will be support available for you - there won't be. Having said that, those years with Dad are precious to me - I am proud to have enabled his desire to stay at home, we had some laughs, we got to know each other (even with his dementia, he was still very much Dad), and I felt I'd given back in some way for all the support he'd given me over the years. My husband was amazingly supportive - and I think our relationship has deepened as a result.
So, that's my story, anyway - I'm not giving you advice, just a bit of insight into how it could be. I wish you all the best with your decision - I know it's not easy.