You should do what you think is right for you... but that is an awful lot of work and time for just a “back up career.” Will the money cover books and travel costs as well (for clinical days)? Time is so valuable to me I would not be willing to spend all that time getting to NP level if I wasn’t completely invested.
If you feel really strongly about your dream to go to CRNA school, then do that. Talk to an admissions counselor to see what will give you the best chance. Get your CCRN, get observation hours. Make sure your grades are on par with their expectations. Retake classes if you have to. Several people I’ve known have gotten in the first time, and some have had to reapply and got in the second time or decided after shadowing a CRNA that it wasn’t what they wanted.
If you do continue with the NP track then apply to CRNA school- it can come across as you being overqualified (they’re both, I think, equal level professionals regardless of the pay difference). Also, they’re going to ask you why you decided NP wasn’t for you. It’s just something you might talk to an admissions counselor about to see what their perspective might be.