You need to get into a wound & ostomy care nurse (WOCN) ASAP! Contact your surgeon's office and get a referral to a wound & ostomy care clinic near you. Get an appointment - and GO!
A WOCN is specially trained to help ostomates - at any stage - with their ostomy: teaching you how to prep your skin for adhering your appliance, sizing the cut hole in your appliance for a correct fit (and this will change over the first couple of months after your surgery as the size of your stoma WILL continue to change until it settles into its final dimensions), how to reduce & eliminate leaks, protecting your skin from leaks and/or helping it heal if your skin becomes irritated, getting your appliance to adhere properly, determining the best length of time between your appliance changes (it varies from person to person), all this AND helping you to determine what supplies suit your needs the best, and to create your own routine for your appliance changes.
It takes some practice, and there will be some "live & learn" moments, but you will find a competent, empathetic WOCN is the best person to help you learn how to effectively, CONFIDENTLY negotiate the logistics of your stoma care.
You're not going crazy, Angel...what you're going through sucks, I know. Many of us on this website have dealt with the same fears, messes, discomfort and embarrassments - 24 hours a day. At times, sleep for me seemed impossible as I was so worried about leaks from under my appliance while I slept. Smelly, irritating leaks can occur often until you and your WOCN figure out the best combination of supplies, their effective application over & around your stoma, and optimum length of time until the next change out of your appliance. Trial and error will be the route you take to become more sure of yourself and how to live with your ostomy.
It may not be easy, but it won't be like this forever! I'm a firm believer that NO ONE SHOULD HAVE TO REINVENT THE WHEEL! Whatever situation you can think of, whatever you have experienced, whatever problem for which you need a solution...? There's someone else who has already experienced it and has come up with that solution! It's just a matter of seeking out the person with the answers. In our case, a competent, caring WOCN!
Reach out to your surgeon's office, and get that referral to a WOCN. You will NOT regret it!
Check back in here, anytime. I'd love to hear how you progress. I'm certain your situation (and sleep!) will improve dramatically. : )