You appear to be an intelligent person that is going through the plight of a career change. It is even more challenging when you are starting a new career and are above the average entry-level age. My previous experience as an intern, I was treated like a joke to some of the company employees. Years later I have long passed those folks by and most are still in the same spot. So I know how you feel, but you can’t internalize how people at your apprenticeship behave, you just have to keep the mindset that you are there temporarily to learn and move on. Appreciate the opportunity to get your foot in the door because paid apprenticeships, internships and shadowing opportunities are hard to come by. If you let this experience poke holes in your confidence you will be stuck.
My advice to you is start thinking now about what you wish your next position to be and start preparing for it, by joining professional organizations in your industry, subscribing to media related to your desired profession, taking coursework, and networking. Talk to people who are where you are trying to go. You can meet a lot of higher ups at conferences. Keep in mind that everyone has to start somewhere, but most people are given the biggest breaks because somebody liked them and/or they kissed the right toes.

Good luck to you!