*Insert Isai reference here*
No really just utilize the negative space of the stage. Its a little hard to explain, but think about battlefield. If they spawn in on the left platform, you need to move to the right corner or right platform and anticipate their movement. As they take a path towards you, move the opposite direction like a yin and yang.
There might be a psychological factor playing in as well since you acknowledge that you have a problem with this so you're always thinking about it in the back of your head whenever you take a stock. If you can convince yourself that the only thing you have to do is evade them for five seconds, there's a high probability that you'll do just fine.
Try to take advantage of Falco's movement options around the stage. The only unique circumstance is FD, but for all the other stages you could practice platform cancelled Phantasms, wavelanding across different surfaces, dashdancing, or really anything that you think might cross up an opponent. If you get this down, you'll be back to SHLasering and Nair approaching like a good little Falco in no time. Good luck!
TLDR: get gud scrub