At some level you need to have faith in your child. It is also a very good idea to maintain communication with your child.
Keep in mind that colleges and universities are sort of like a half way house between having your child living at home versus living on their own. There are support systems at university. They have people they can ask for help. They also have you who they can call when they need help.
Stuff will happen. There will probably be a breakup with a significant other at some point. There might be a disappointing exam result at some point. However, we get through it. Us parents were young once, and we got through it. Our kids will also.
Set a budget. Stick with it. I think that it is a good idea for the child to largely be in control of the process. You help your child when you can.
Attending a “big name” undergraduate university is not essential. MIT graduates work for U.Mass and UNH graduates all the time. UNH and Rutgers graduates just might attend Stanford or Harvard for graduate school. In our family I did go to the “big name” undergraduate school and found it was probably not the best fit for me. My wife and both daughters attended more normal undergraduate schools (two were ranked in the 100-120 range, one was a small university in Canada that the vast majority of Americans have never heard of) and each of them did find a good fit. All four of us got accepted to very good graduate programs that were good fits for us (or are expected to be, one doctorate starts later this year). The ranking of the school where we got our bachelor’s degree did not seem to matter for either finding good jobs or getting accepted to graduate programs. What we did while an undergraduate student and the work or research experience we got both while an undergraduate student and in a couple of years of work after getting a bachelor’s were in all four cases much more important in terms of getting into a good graduate program and in terms of doing well in life and in terms of finding good jobs.
We still pay for our kid’s cell phones. We text or call regularly. We keep in touch and still help them when we can.
Both daughters appear to have found universities (one each for a bachelor’s, a different one each for a doctorate) which were good fits for them. Finding a good fit and finding a school that is affordable is important. Ranking is not.
Regarding shingles, this sucks. I had shingles once probably as a result of jet lag after three quick international trips in a row (to Europe, Asia, and the opposite coast of North America). Hopefully you have gotten appropriate medical treatment. At some point you will probably want to get a shingles vaccine. I personally had some recurrent pain after I got over shingles, but the pain went away after I was vaccinated.
As a parent I think that we mostly need to have faith in our kids, and learn to relax. They will figure it out. We will help when we can.