On the other hand, starting with 4/week as a goal is terrible. Sure, you might be motivated enough to actually do it for a few months, but the risk of falling off is high.

Much better is to start at 2 or maybe 3 times a week, always leaving you slightly hungry for more. Even if you get sick or hurt at some point, you'll have much more drive to continue if you're not already at the limit of your motivation

This is the way.

I’ve been going to the gym regularly now for over a decade.

I have many days where I don’t want to go because I have no motivation. I tell myself I only have to put on my gym clothes and go through the motions. If I hate it after 10 minutes I can go home. I always end up there for at least 40 minutes this way because by the time you’re at the gym with your shorts on, it’s very much like “well… I’m already here…” It might not be the greatest workout, but consistency of just showing up is the key.