Congrats on going up at least. It’s still low but better than before. I recommend heavily studying using Gruber’s, Barron’s, official books, and Princeton Review. Online resources are a wonder too. I had a 59 CR PSAT and managed to get it up to a 760 and a 36. I used Barron’s SAT 2400, ACT 36, Barron’s SAT Critical Reading Workbook, Gruber’s SAT Critical Reading Workbook, official books, PR SAT Power Vocab, and PR Cracking the ACT. SO improvement is possible.
I personally used all SAT books to study right up until…2 weeks before the ACT date? I basically used ACT books to get a feel for the format and timing, and to work on the Science section. To me, the SAT books can be used to gain an understanding of the content in the sections but it shouldn’t replace an ACT book. You can hang at a bookstore and leaf through the study guides, buy used books at a cheaper-than-retail price, or take books out of the library if finances are an issue.