You’ve honestly used the best resources imo. Have you identified your issue? Is it content? What I used was PREP, med study books, med study qbank, and true learn qbank. True learn was dog water. I spent ~30% of the time reporting wrong answers.
PREP is going to be great information but harder questions than needed. The important thing with this resource is reading the entirety of the rationale even if you got the question right. They give such in-depth answers that you will get other questions right on the same topic.
Medstudy is by far the most similar question style to the real thing. You should do this qbank as many times as you can. Shooting for approximately 80% by the time you’re done appears to be a correlation to passing from what I read online and my friends that passed.
Medstudy books are high yield and detailed. If your issue is content then you should definitely give these a pass. They can take some time if you are reading them for understanding not just for review but I attribute these the most to my content understanding.
The ABP practice test obvi it’s written by them so high yield and like the real thing but small number of questions. I’d use this like a week out to see what you got wrong and go review those topics. It’s surprising you got a 70% both years and didn’t pass seeing as they state that the 70% usually correlates to a pass.
Depending on what your career looks like, consider taking the American osteopathic board of pediatrics (AOBP) certification as well. It’s a good option for general pediatricians and community pediatric hospitalist that don’t require the peds hospitalist fellowship (don’t get me started). The only subspecialty board they have is NICU and allergy so if you’re doing another this wouldn’t be an option. Imo they kept more strictly to knowledge I’d expect a gen peds doc to know compared to ABP where there was a pretty decent amount of too in-depth knowledge for gen peds. They also just opened it up to MDs to take with the merger. If you aren’t a DO, don’t worry there wasn’t really OMM stuff on it. You could easily get every single one of those few questions wrong and still pass. From my understanding the first time pass rate is about where other specialties are (and should be) somewhere in the 90% and not the trash that ABP (I think was like 78% when I took it) for no reason.