Such a lovely story! If I knew how to do anything related to mods or that whole side of Minecraft, I would offer my help, but unfortunately, I don't know much besides skinning (haha). I really hope you reach your dream. I would suggest browsing the community, asking questions, or getting in touch with people who can help you. You're on the right track with YouTube videos, as I believe those will be most beneficial to you. I would also suggest breaking down each part of making a mod, and working on one segment at a time. It seems you're getting close but you struggle with certain things and you hit barriers. When that happens, I believe that would be the best time to ask questions or search it up! Other places that might be beneficial to your cause might be Discord servers or other communities outside of PMC :)
If you need anything or any further help I can surely try my best to help you! If you need a skin or anything, DM me on here or on my Discord (chloe#9750) and I can make you a skin, but that's as much as my help extends to :)
