Pepper2013, welcome to the forum! There is a TON of experience and advice here to help you adjust to the new “ears”. Congrats on the new aids … BUT! You have already raised a few big red flags with your posts here.
1.) Travel time to Costco is simply unworkable in the long run. Even if you keep a journal of all the issues you’re having, what are the odds you’ll get back to Billings while the weather’s good? What about future emergencies or service req’s? It’s going to be BIG challenge. Are there no audiologists closer to you? Maybe post your location and ask the forum here for recommendations - or try your state board of hearing specialists?
2.) Sound quality of your K7s is AWFUL when playing instruments. Since this is an important pastime for you, the situation is less than ideal. How are the aids in other settings: the home, noisy restaurant, on the phone? If you have more than one area of poor listening experience, these aids are not tuned for you. Typically, a new purchase of aids requires a half dozen follow-on visits to straighten out the tuning & program set-up. Start by writing down what program covers what use, so you can refer to that until you memorize it (e.g., Program 1 = default, Program 2 = noisy restaurant, Program 3 = music, etc.,). Aids are programmed using the audiogram from your hearing test - that is likely on file at Costco, if they did the test. By NO means does that audiogram result in a perfect setup for the aids, tho! At the minimum you’ll need to get back to Billings and collar that audiologist for some quality time, given your travel distance. Is this sustainable?
3.) The aids make your ears itch like crazy. Uh-oh, big time! I have been that route, and can tell you, if the aids make your ears itch THIS soon, you will head down the road to inflammation and possible otitis infection in no time. NO anti-itch cream is a substitute for a proper material used. It could be that you are allergic to the materials in this aid (not sure if they are behind-the-ear or hard case in the ear). This problem will not resolve on its own - neither will poor fit and rubbing or irritation of any kind.
4.) Audiologist at Costco has poor attitude and seems unwilling to really work with you till your comfortable, enjoying the aids and SATISFIED.
When you add all these up, my mind screams: RETURN BEFORE TRIAL EXPIRES! No kidding, you can save a bundle of dough getting aids at Costco, but at what total cost? The aids sound like they have not been set up to your listening preference, the sound quality is harsh and unnatural, they are uncomfortable to wear, and you still paid money for them. Nope. Not a good deal.
Please don’t be discouraged, cuz attending to hearing is PRIORITY #1. But put your needs & preferences first, also the practicality of having a medical device that you rely on but which also needs occasional servicing, replacement & repair. Let us know what you end up doing - bit of a clliffhanger here …