I'm new here and would be very happy if I get genuine help and advise.

Me(non eu)and my partner(dutch)living in uk nearly 4 years.my eea2 visa expire after 1 year and things are not going well between us,as we planning to mutual separate/ divorce,their is lots of question going on my mind.we are not quiet there yet to do divorce!! My question is shall I apply for dutch passport as I married with her more then 3 years.in this case what do I need to do apply,
Another question is should wait for divorce then apply for retain rights?
Please note that I'm not sure weather my partner will help me after divorce,things between us may get hard also my partner exercising treaty rights since living uk.
Please I need advise regarding to keep myself legal in uk not in personal life advise. Thanks