I lost my W-2 how can I file with my last check stub

You need to contact the issuer of the W-2 you lost, and ask for a copy. While you can file with your last paystub, it does not have the detailed information necessary for you to complete the tax return, and your return will most likely be wrong.

Your first course of action should be to contact your employer for another copy of your W-2 since you lost your first one. 

Then, take a look at the information below for more advice.

https://ttlc.intuit.com/replies/3301808

https://ttlc.intuit.com/replies/5451995