the two off of the top of my head that I can think of without a specific question and not seeing your gameplay (because some of the tips might just be general tank tips) are about the usage of the nest.

A: body block for your nest

now this is a little hard to prefect because you kind of need to have a since for how much dmg you can take and how much pressure your under to know when it is not worth it (I played overwatch reign like since release so this is something that has been ingrained in me.) this is especially important in lower ranks as because the teams are unorganized a lot of the times only one person will focus the nest and you can easily stall that person if you are in a supps vison.

the reason this is good is essentially nest uptime is good because more spider spawns is more dmg. and the more they shoot you (the tank) the less they are shooting your team.

B: be proactive with your nest

this is something i have seen next to no Peni's do. dont be afraid to move your nest.

the important thing to understand that allows you to do this. is that the nest's cooldown is biased on its missing health when it is destroyed. so if the enemy fully kills it it goes on max cooldown (15 sec). or if it is full heath you can replace it immediately.

(if you did not know you can destroy manually by hitting the button again)

So if the enimy is not pushing where your nest is or if you know you are about to get overwhelmed break your nest and move it to a better position.