Don’t worry. UML is just not very good. I have tried it myself and I also have never seen a decent sized project that was designed successfully with UML. People don’t understand the diagrams and they are hard to iterate on. Working with UML is tedious instead of supporting you.
I use it too for first thoughts about the project. It is also a decent reference. But once the project has a "personality" the UML goes away pretty much. And only the complex stuff needs the UML. The simple patterns are complete unto themselves.
