An unavoidable long distance relationship tore us apart and I am at a loss as how to proceed

[s3vel2]

We've know each other for soon to be 27 years. We are both from the same small town were I still live but she lives about 900 km (550-ish miles) away since about 18 years. She comes here every summer to stay at her cabin for 3-4 weeks. We were close friends. Her children (with another man) has nicknames for me. Last summer we suddenly fell madly and deeply in love with each other. 

I too have children from a prior relationship. My youngest won't be moving out for at least 3-4 years, and her children are just 9 and 6 years old. Neither of us will be moving any time soon.

Now,  9 months and not an insignificant amount of money spent on plane tickets later, is it clear that the dynamic of this relationship is killing us. Both of us. The periods together (about 1/5 of the time) are intense, almost too much so. Deep talk, crying, intimate physical contact whenever the opportunity presents itself. In contrast, the long periods apart feels like a gray mass of... nothingness.
The constant back and forth is too much for either of us. Neither of us can bear it any longer and yet neither of us wants to end it.

But we just did. For both our sakes.

How? How can I possibly move forward? There is noone what will ever be able to match what she means to me. The prospect of going from twenty-seven years of shared memories and moments to meeting and getting to know someone new - I don't think I can ever do it.

Any advice?

[Gebidozo]

If you really love each other so much I think you should get through those several years and then find a way to live in the same town or at least closer to each other.