As comment to the Danish translation you find the following translation :"This damned life will take you away from me so cruelly. What can I do?" This text I find correct.
Ok guys, it seems to be clear that we have an "if" clause here, but the tenses to be combined are: "What can I do if (...) life is so cruel..." the rest has nothing to do with the choice of tense for the conditional.
The only part which could be in future (because of the "if" ) is that "What can I do". In that case it could be: "What will I do", however, I don't think it's necessary, since "What can I do" is an expression meaning "I can do nothing". See what I mean?
For a "meaning only" translation, to me, Serba's line sounds correct. If the meaning is the same as in the original, I don't think we should change the verb tenses at all.