Rough watch, and way too much like my day job to take it as "entertainment." It did have the result of making the recent show The Curse seem like a happy-go-lucky, people-are-wacky jape, something I didn't think was possible.
Difficult (impossible?) to like either of the two main characters: feasible, perhaps, to find something approaching empathy for them, but from a substantial distance.
At times I found myself wishing for dire revenge against Martha, alternating with loathing for Donny and his jarring, self-destructive draw to someone nakedly out to ruin him and those in his social world. Certainly not unheard of in non-TV life, but wow, so dismal.
Not sure there are any lessons here, or anything approaching depth and illumination to aid those affected by stalking and related abuses. More of a slow crawl witnessing of a bloody catastrophe, with attendant feelings of helplessness, and pessimism about humans generally. Who needs that when the news media fills that, um, void on the regular?
Approach with caution and avoid trying to binge-watch more than a single episode - consider a binge of this as making it through a single episode without a pause (or three) to dry heave.