Dear all,
Firstly, I'm a new member, so if this problem is not posted in the right part of forum I hope that it will only be moved to right part and not deleted.

I'm having some problem with programming loop in mathematica. I'm working on an plasticity algorithm which has to be updated for any new step.

My opinion is that there should be at least three loops. The problem is that I don't know how to connect it.
I've manage to do first part of the loop, until F is less than 0. Loop also calculates next step when F becomes larger than 0. In that moment correction loop is needed.

Any help is welcome
Best regards
freequo