TBH, my advice is the same as it would be if you had hung onto the 3.8:
Build your list from the bottom up.
Starting from a mindset of “all my hopes and dreams will fall apart if I don’t get into a T20” is terribly unhealthy. Only a tiny minority of US college student attend one of these super-elite schools; and there are hundreds of thousands getting a great education and having a great college experience at hundreds of other reputable colleges.
I see from your other thread that you’re in Washington. I realize that this puts additional stress on you, as an aspiring CS major, because UW-Seattle CS is so hard to get into, even in-state.
The sanity-saving (as well as practical) thing to do is to find at least one or two affordable schools that are very likely to accept you and that you could be happy to attend. Table the whole “T20” line of thinking until you have accomplished this. Everybody needs a balanced list; and that shouldn’t mean having “safeties” that you see as a fate worse than death. You’re a strong student, and there are great schools that would be happy to have you attend!
Grade-wise, do the best you can in the spring semester, obviously. Communicate with your guidance counselor - do they already know about the issue(s) that caused the grade dip? The counselor recommendation is where extenuating circumstances should be explained, and your counselor can do a much better job of this if they’ve been following the situation all along and observing how you’ve dealt with it.
Instead of fixating on rank, think about what kind of learning environment you want in a college. School size, geography, urban/suburban/rural, the “vibe” of the campus. Would you enjoy a STEM-focused school, or one where there are lots of humanities and social science majors as well? What’s your budget, and are you eligible for need-based financial aid?
Once you know that you’ll be okay, even if you don’t get into a super-elite college, then you can think about some well-chosen “reach” schools. Focusing on “dream schools” first is a recipe for toxic stress and misery. People here will gladly help you to brainstorm and build a balanced list - from the bottom up.