Remember you can always call the USA, at no cost, from your computer. It is an important thing to always have ready for emergencies like your issue.
There are many options. Google Voice is one of the best ways. Setup from your computer using your existing Google/gmail account or signup for a new one. GV will ask for your other real phone number (USA iPhone number) and send you a message to prove it is you. Then GV will give you a new USA virtual phone number. If you are not using a VPN on your computer, Google might tell you to wait until you are back in USA. Add it to your task list for next flight or get a VPN.
Skype installed on your computer is another good backup for calls. I have a balance of $8.xx of a $10 prepayment I gave them many years ago.