Questions in essays: should be followed by a question mark or a period?

If you use two questions in one sentence is it necessary for a question mark or a period.
EX: What would I do without her, would my life be the same

Question mark or period?

I say question mark. Since you separated by a comma I think it will be fine like this:

What would I do without her, would my life be the same?

If you are asking a question, you should use a question mark. In the way cj phrased the questions, maybe a semi colon would be better.

What would I do without her; would my life be the same?

This is a run on sentence. It is a particular kind of run on sentence called a "comma splice."
It is not a bad mistake, but it is not quite right.

option 1
What would I do without her? Would my life be the same?

option 2
What would I do without her; would my life be the same?

:-)