Intellisense loading forever

Any similar experience or how it can be fixed? Basically whenever I
try to see the methods of a class or refactor something is broken
because itellisense is still loading.

Based on your description, this is quite a strange behavior and in my side(Visual Studio Community 16.5.0), it works well and do not show loading intellisense forever.(If necessary, please provide more detailed info)

So I think there are some problems with your vs environment, please try these suggestions:

Suggestion

1. If your project is created by other previous vs version, please close VS Instance, delete .vs hidden folder, bin, obj folder, then restart your project.

   Besides, try to create a new empty project and test whether this still happens.

2. Delete any vs component caches under C:\Users\xxxx\AppData\Local\Microsoft\VisualStudio\16.0_xxxx\ComponentModelCache

3. Try to use devenv /safemode to start VS, then open your project or disable all third party extensions under Manage Extensions menu to test whether this behavior is caused by a particular extension. And some third-party extensions probably interfere with the execution of the vs background tasks, causing congestion.

4. Try to do a fix in visual studio to check whether VS is broken.