Struggling with mctip sa

I am using the ms press 2nd edition books and trainsignal - watched trainsignal and really enjoyed it and felt I learnt lots. Going through ms press 640 R2 book and struggling - some chapters are v good, for example group policy - liked it understood it. Onto DNS a subject which I think I know a bit about but I am reading a page and forgetting what I have just read/ not understanding it - has anyone else had this problem? Getting a bit stressed
Comments
Good luck!
Current Certs: MCTS | Network+
Currently Working On: CCNA
2020 Goals: CCNP Enterprise, CCNP Security, Linux+
DNS is covered much better in the 70-642 book IMO. I suggest reading the relevant objective sections in all three of the MCITP:SA training books to get a better handle on the material. You will find answers for each exam overlapping between all the books not necessarily in the "correct" guilde.
Finished!
On to VCAP!
Worst case scenario (I actually did this as I was getting nowhere) complete the rest of the material and then start with the 642. Once you complete that you should be OK