I also used to think poker sites were rigged. It was comforting to think that my defeat was due to the room's cheating, not my lack of skill. But over time, I started winning some tournaments and reasonable cashes. Even in the infamous 888Poker Blast, once, paying $1, I got $100. I came in first and won $70. How could I achieve these results if the site is rigged? Then I realized the essential:
Poker doesn't owe me anything. Poker rooms don't owe me anything. Online poker really is crushing. But it's crushing for everyone. Learn to play, and the results will change. And don't think that online poker is the same as in-person poker. It's not. It's completely different. Accept this and relearn how to play, because poker is constantly evolving, and the strategy that worked yesterday could lead to your ruin today.