Student or Learner
My dear teachers,
Is this grammatically correct?
That was never the way I planned, not my intention.
I'm sure some other native speakers will dislike the use of "never" in this context and suggest that it should simply be "That was not ...".
The second half does not match the first. If you use "never" in the first, match it with "never" in the second.
Given that you have used "my intention" in the second half, it would be better to match the first half to it. My suggested final sentence would be:
"That was never my plan, never my intention."
There is a danger of it being a little tautologous because "plan" and "intention" are similar in meaning in some contexts. However, I think there is enough difference for this to work.
Remember - if you don't use correct capitalisation, punctuation and spacing, anything you write will be incorrect.