how do i recover a text I'm typing if an incoming call comes in on my iphone?

Since they are different apps altogether, when you answer a phone call, and then return to the message app, it should be where you were when you answered the call. At least it is that way for me. Don't close the message app, just answer the call. Then when you end the call swipe half way up your iPhone screen and you'll see all the apps you've recently used. Tap the message app and it should have held your place when you stopped to answer the call.