Can i file just useing my last paystub?

NOT a wise decision although no one is looking thru the screen to see what you are doing.   The W-2 forms have to be mailed by 1/31 so just hang in there.  Make sure the employer has your current address. Check with them to see if you can pick it up in person or if they have online access for it. 

More times then not if you file with the last pay stub the figures will not match the W-2 and then you are forced to amend the return later and they are taking more than 6 months to process... again not a wise choice. 

It’s easy to get the numbers wrong, because few taxpayers have a good understanding of how different pretax and after-tax employee benefits affect the W-2. If you get the numbers wrong, you have to file an amended tax return and that will take six months to process and could delay any refund you want to claim.