Much good advice above.
I won’t repeat but will just add my OTC: In a safe environment, being absolutely sure that you know how to wet-exit or even better have an experienced kayaker on stand by, feel out the “point of no return”.
Because of your “irrational fear”, you probably stop your edging and leaning long before you reach the limits of secondary stability. The tipping point thus remains an unknown that will arrive suddenly and unexpectedly, undermining your confidence.
Aggressively find that point - if you go over you wet exit and try again. You should try without spray skirt first, with spray skirt only with a competent paddler next to you.
Youtube “How to edge an lean a kayak” by Gordon Brown (paddling.com within Youtube). There is a whole series of edge and lean drills if you follow that lead.
The Inside low brace turn is extremely helpful in finding out how much you can lean a kayak into a turn. The outside low brace turn gives you support when finding how far you can edge. Both are fun and dynamic maneuvers that’ll go WAY beyond primary and also secondary stability and will boost your confidence. You can theoretically flood your cockpit with each maneuver if you don’t use a sprayskirt, they can be executed that aggressively. Both maneuvers should be properly demonstrated to you in-person, though. You can make a lot of significant mistakes.
A summer lake session with seasoned paddlers would be ideal.
Good luck and don’t buy a freighter!
Andy