Much like Windows Visual Studio has a “safe mode”. This safe mode loads Visual Studio without plug-ins and extensions.
I loaded something bad this morning and couldn’t get Visual Studio to start. It would just hang at the splash screen.
You should simply be able to hit [WIN]+R and type in:
devenv /SafeMode
Once it has loaded go to “Tools” -> “Extensions and Updates”. You’ll be able to see all of your extensions installed. Start removing the most recent additions till you can get it to start without trouble.