You are welcome!
I just realized that I should add 2 more points:
1. I don't know what your current stop-loss is, but for PLO it should be 7-10 buy-ins and you should be having at least 50 buy-ins for the limit that you are playing. The bigger your bankroll (measured in buy-ins), the less reasons to tilt because the bigger it is, the smaller the percentage you lose from it in a downswing.
2. There is no downswing. There is no upswing. There is only the current hand. Upswings and downswings are just a product of our imagination (and a product of pokertracker's or hold'em manager's rendered graphs). Once you stop thinking about them, they cease to exist. One of the best things you can do about your poker career is stop looking at the cashier/graphs. Only check them one predefined day every week. If you can follow this advice, you won't even need a stop-loss. I recently had a very big downswing in NLHE cash games in a single day and, by the end of the day, I recovered everything. If I had a stop-loss or if I realized how much I was down that day, I'd have never recovered the money. Stop wasting your concentration on results and start focusing on solid gameplay instead.
To remove temptation to look at your graphs, configure all of your pokertracker or hold'em manager tabs to not show any stats about your winrate (or total profit/loss, of course) except a single tab that you will never open until the day you are supposed to. This way, you can still review your stats without seeing your results.
I also strongly advise you to read "The mental game of poker" by Jared Tendler. I also hear Jeff Hwang's 4 Omaha books are some of the best on the subject.