I'm a partial transmale who spent my life living as a female, but having a mind wired more like a male.
Females, especially religious ones, tend to use passive aggressive/religious guilt methods to punish/control offspring who aren't living exactly as they wish.
My mom would stop writing or contacting me when I was at college if I said anything at all that didn't match her beliefs, to punish me.
My sister still does this.
Being of a male mind, I either didn't notice or didn't care. If my mom didn't write me, I never missed her letters because they were mostly lectures on what I should be doing. I make sporadic attempts to communicate with my sister but she has been annoyed with me most of my adult life due to my clueless male behavior.
I did become close to my mother in last five years of her life, when I lived in the same house but that was only after we did a bit of emotional healing stuff, and none of it had anything to do with my being partially trans, since I only realized what I was in 2013, and my parents passed in 2008.
You don't have to obey your uncle at all. Just laugh and say something glib about having other plans, and if they get pushy, just say "Naw, I don't think so," and immediately change the subject.
Maybe it's time to make new connections and friends who accept you, and let your relatives sort things out for themselves. As long as you are needy and beg for their approval, they can punish you for trying to be yourself.
Here is a link to resources in transgender Switzerland, and I'm sure there are many more. Maybe you could attend a support group, or find transfriends nearby:
https://www.angloinfo.com/how-to/switzerland/family/lgbt