The average life of a hip replacement is reckoned to be 15 years. However, many people have had perfectly good artificial hips for many more years than the. It's just a matter of luck, and, I guess, body weight too.
This is why they don't want to give you a full hip replcement too soon,as a revision of an old hip replacement is quite tricky.
I looked at resurfacing, and was told I was too old, while I was, like you, declared to be too young for a full replacement.
I have now had both hips done, and my life is much better as a result. I am 67, and was 63 when the first one was done, and 64 at the second time of asking.
From what I have read of resurfacing, it is the best way to go, but it's not easily available on the NHS.