I think you need to check why the phone can't boot as normal, you can try to connect your phone to computer, if the computer can't regard the phone as the drive, it means your phone become a soft-brick. That's possible to make it work again, at this moment, you need to flash your phone by flash tool. You can search for solution in XDA forum, there are more details of tutorial. After flashing system, you can use Android data recovery tool to recover lost data from your phone, such as contacts, text messages are possbile to get back.
Anyway, if your phone can't read by computer, I am afraid that you have to ask professional reparir service!