Here is the situation: I am working with 2 others on a paper A, and simultaneously by myself separately on a paper B (which is a thesis).
A and B are on very much similar topics.
I started with paper B slightly before we started working on paper A, but the ideas in paper B build upon the ideas in paper A.
Moreover, paper A will very likely be published sooner than paper B. My plan at first was to cite paper A in paper B.
However, my other 2 co-authors have now started to shift their idea about what domain of paper A should be, and they are shifting towards the topic of my paper B, and have even started to reinvent some of my ideas in paper B.
Therefore, I am very concerned that this will cause a plagiarism issue: If we decide that paper A should contain many of the ideas in paper B, then ideally, I would want A to cite B: I came up with these ideas independently and for a different paper, so if A wants to use them, paper B (i.e. myself) should get credit for the work (since I put in all the work and came up with it first, and we originally didn't plan to put it in paper A). But paper A will likely get published before paper B is handed in as a thesis.
Most importantly: I need to hand in paper B as a thesis, and I cannot afford not to hand it in, or to make a completely different thesis. Therefore I need to be sure that paper B does not commit (self?) plagiarism.
Is there a way for paper A to cite paper B (my thesis), even though paper A will be published before B?
If no, how to avoid (self?) plagiarism in this situation? (somehow integrate parts of B in A while still recognising B as the original work that is a separate thesis and gets credit as such?)
Is it generally stupid to work on two papers simultaneously like this? Did I make a big mistake...?