Mystery/love story told in 1st person from Male POV who falls in love with a woman. He describes how much he loves her but doesn't feel worthy of her. Everyone shares concerns with his choice

[Lana]

I read the book ~ 1984. The book is told in first person from the male point of view who falls in love with a woman. He describes how much he loves her but doesn't feel worthy of her. Everyone shares concerns with his choice - including I believe his mother and sister. I was reading a lot of Fred Mustard Stewart and Phyllis Whitney at the time- could be one of theirs or maybe an author in that same area alphabetically. I vaguely remember them all being in the same area of the library.

Spoiler...

He kills her in the end- and you realize the concerns were not for him but what other's knew he was capable of.

[Lobstergirl, au gratin]

Where and when is it set?
What's the tone? Brooding, suspenseful, scary?
Cover?

[Lana]

The book was on the suspense side and may have taken placed in the English countryside. I don't remember the book cover at all. I remember throughout the book he talks about how wonderful and lovely she is. If memory serves, in the end he takes he up to the top of an observation deck ( maybe?) and pushes her off.