My highest SAT score remains a 1490 (math 800 and reading 690) with a 21/24 essay (doesn’t even matter and it ain’t even good either). I took the ACT but only received a 29. I’m retaking it in September. I’ve been prepping for it since April, but the highest total score I can get on practice tests is a 32. I’m an Asian male, so chances of even getting into honors SUNY’s looks slim not to mention top public and Ivies. Is this good enough for Cornell? University of Illinois Urbana Champagne? SBU Honor’s College? Any college?
find the colleges’ common data set to see the score range for their middle 50%…
You should only retake the ACT again if you are a rising junior since your SAT scores are fine.
But if you still wish to retake the ACT, I took a lot of practice tests and only got about 31-32 but on the actual test I received a 35 on the second time I took it. Your scores are not very competitive for top Ivy league schools, but I think you will be fine for SUNY schools. Your SAT score will be sufficient.
I’m just nervous about doing worse on my retake 
Your SAT is way better than your ACT, so I wouldn’t worry about the ACT at all. Would work more on SAT IIs and applications. Can’t tell about what schools you can get into, as it depends on grades and other things. 1490 on the new SAT is fine though.
Your 1490 is in the middle 50% range for almost all top colleges, which makes you a realistic applicant. Admission to top schools is tough for all applicants, and holistic in nature, but your test scores are not atypical. If I were you, I would concentrate on making the rest of your application as strong as possible.