Ouch. Difficult decision ahead. Be 30 years old. Have a decent amount of experience on the .net stack.

Ditch it all and go all in on Java EE or continue to pursuit mastery of .net?

Do you have any specific reason to make the swap to Java? Follow opportunity not trends I say.

What is your motivation for switching?

@codetinkery my motivation for switching is opportunity, I have a good job doing .Net but started to wonder if I am spending too much time in the comfort zone when I saw an opening for a Java position.

Real mastery of something makes you invaluable. Dev jobs pay well because there are so few of us. The best paying jobs are the skilled ones where there are the fewest people who can do it. Becoming a .net master/guru means you're 'the special' when someone's looking to have a .net project done right.

Why not just do both? C# and Java are very much alike, its just the frameworks that you need to master.

You're right. Maybe I am overcomplicating it.