Can I file bankruptcy even though my income has dropped significantly?

It is better you contact a bankruptcy attorney and discuss with him.

What s your plan- filing chapter 7 or 13?

Do you have enough assets that you want to keep? As per your given information, I believe chapter 7 is good for you. But, it would be better if you can provide us a better picture of your finances...tell us more about your debts, expenses, income, investments, assets..etc.

You can but have to qualify the means test.

Chapter 7 is what you can qualify for. Check out other eligibility requirements.

You can file bankruptcy whenever you want. But count in some factors here:
If you want to take help of bankruptcy to clear your debts, then you can go for Chapter 13.
With a chapter 7 bankruptcy, you will be liquidating some valuable assets.
Bankruptcy is going to hurt your credit report a lot.
But first of all, try to find a job. Money is time mate!