Low GPA, High Test Scores. What are my chances? How can I improve?

Hey everyone! So I’m a Junior attending a “gifted” high school in Florida, where all my classes are (at least) honors. As most gifted students do, I suffer from anxiety/depression/ADD etc. and it really hurts my grades.
Throughout high school I’ve found myself with a lack of motivation, and my grades suffer. Right now it’s at about a 3.5, and going up. However, I usually score really well on standardized tests: I got a 30 on the ACT I didn’t study for, and I got a 1400 on the PSAT (I’m scheduled to take the SAT March 5th, wish me luck!)
But if I want to get into a more selective school, (Washington University has contacted me over high PSAT scores, and I’m considering applying) will high test scores be enough?
Basically what I want to know is- how can I get into a selective college without looking like a waste of talent? I know I have to improve my GPA, but is there anything else I can do? Anything to stand out?
Thanks so much in advance for your response(s)!

I had to learn the hard way that the PSAT (and the subsequent letters you’ll get from it) don’t mean anything, and although they’re indicative of standardized test skill, they don’t guarantee anything for what’s to come on a real SAT. Right now, focus on that 30 ACT, you can ride that all the way home, and you’re still a junior (sophomore even?)! Florida is generally looked at as an academically weak state, so it helps that you go to a specialized high school. My guess is with a few more A’s the next few semesters, you’ll be in to WU without a problem. Good luck!

Your GPA and your scores are enough to get you into a number of really good schools. No, probably not the super-selective schools, but don’t get hung up on that. If there’s something that really appeals to you, focus on that in every way possible (ECs, classes, teacher recs, etc.) and make that the focus of your application. And if you can, visit schools where you want to apply and see if you can make any connections in those departments. The lousy thing about high school is that you’re expected to be good at everything. In college, and then in life, you can focus on what you like. So if you do a bit of that now, you may be able to overshadow some of your less stellar moments earlier.

And I agree with @gatorgirllala on not reading too much into the letters you’ll get from schools based on your test scores. Part of how colleges make themselves selective is by getting a lot of applications, and part of how they do that is by soliciting them. It’s great to use those mailings as a way to find out about schools, but that’s about it.