I already filed my taxes, I was supposed to prove my identity in person but the offices closed due to corona virus . how can I get my taxes and stimulus check now

You should call the number on your IRS letter to find alternative options.  Many times you can complete an identity verification over the phone.  Here is a link with more information on the process.  

Having the same problem 

I did that already, there is no live help and online you have to have a mortgage account number, loan, or school loan or car loan account number and I don't have any of that