Why is my blis rating so low?

I studied openings, and I usually play the Italian with White and with Black against e4 Sicilian and against d4 a "system" like the Queen's Gambit Declined, I train tactics, I have +2000 in tactics, and I think that given my playing strength I should have at least more than 1200, I used to have more than 1300, but it seems that many have evolved and the difference between the guys with 1200 and 900 is not as much as before, but sometimes I wonder how someone who trained tactics and studied to only have a 900 rating, the result is frustrating! I have played against some opponents from 1800 and 1900 and the level of play was the same, and they themselves asked why my rating was so low when playing at a much better level, and I have two answers: one is an evolution of the others and I have a genetic disease with no cure, "Bipolar disorder" which basically has moments of "Euphoria", "depression" and my regularity, and I do treatment, but even so I feel a difference, it is not the same thing.

I don't feel bad so much about the rating, but because I know I can play better and I demand more from myself for that.

Thank you in advance!

Nice. We have to deal with what life gives us. Best of luck. I try different openings, but it is my mid game that struggles.

Don't worry about the rating! internet ratings are not very accurate and vary very often, we are probably better off reading chess books and analysing our games than stressing out on blitz or bullet