i absolutely loathe installing mechanical FDs, so rest assured, you're not alone.
Usually it ends up working. Sleeping on it usually helps.
If you want to get creative, consider buying an old shimano 105 FD for cheap. Some models have long lever arms, making pulling the cable much easier / better shifting, especially valid in fully integrated rigs. For 20$ or thereabouts, it can be worth it.
Or, buy that more recent one: . This one should be as good as it gets.
Either could be worth the expense vs hitting your head against the wall and wanting to throw the bike out of the window. Speaking from experience...