I’m not sure what you mean by tactical shooter but flathub has a subcategory for shooters in the games category. While half of them are source ports of Doom, Quake and some other games, there are a few games I’ve looked into that seem interesting. So far I’ve only played Empty Clip and that’s a pretty good top down shooter with rpg elements but games like Red Eclipse and Tremulous look pretty interesting as well.
I’ll keep it brief because I know that this kind of stuff is very triggering for some people but when I was in elementary school, my dad was an alcoholic. One year on my birthday, we decided to go out of town so we can eat at a restaurant that we didn’t have and buy some games from GameStop. Long story short, right before we reached our destination, my dad for a reason that I don’t remember (assuming there was one), decided to start physically abusing both my mom and my sister. So we ended up just going right back home and we just ordered pizza.