Is it possible to self-study SATII US History in 3 months?

Hi, I’m a rising senior. I’m hoping to get another SAT subject test done, but I’ve never taken US history before (I’ve only done world history). I’m hoping to take the test in October or November, which means I only have around 3 months to study. I only have a book from Direct Hits and I’m planning on watching crash course. I’m also currently studying for the ACT (I’ve taken SAT, but I’m hoping to boost my score). Do you think it is worth the time for me to study for SATII US History or is it very unlikely and I should just give up?

Much thanks!