Leverage is being good enough that walking away from you costs them something.

What gives you weight in any arrangement is the cost of replacing you. Not how liked you are, not how long you have been there, but what breaks if you go: which shifts go uncovered, which jobs nobody else can do. That cost is something you can build deliberately, and it is almost always built out of ordinary reliability.

Ask what would genuinely be difficult about replacing you where you are. If the honest answer is nothing, pick one thing to become the obvious person for over the next couple of months.