Pseudomonas are everywhere.
I used get the flu every winter, an occupational hazard for teachers, but because of lifelong upper respiratory issues, it generally became pneumonia. The predisposition was (is) there, just as it would be for you with COPD. I had flu going to pneumonia six times in maybe 8 years, including one bout that resisted antibiotics for a while, but since I went with annual flu shots, I've had 20 years clear.
I actually have a point, in that when you have a pre-existing respiratory condition, and as you age, you have to be careful. I've never heard of inhaling pseudomonas as a cause of pneumonia, but if your immune system is run down, you have to watch it. You're still far more likely to become ill from a cat or dog (or other people) than a fishtank, but if you suspect a possible connection, extra hand washing etc might be in order. I know I get a little cavalier about being cautious when I work with my fish.
Take care and give yourself time. Pneumonia knocks the stuffing out of you, and it takes weeks to get back to 100%, even if you're young. From reading you, you're a strong character, but an illness like that has to be respected. You can't just push its results away. I'll say get well soon, but what I mean is accept you'll get well slowly and steadily if you give yourself time to recover.