As far as fitness points go, yes you lost that according to the algorithm they use. Those numbers really indicate the long term training load compared to your ability, not really a true indicator of your relative fitness on the bike compared to others or even yourself one month ago. I use another application to track similar numbers and I was sick for four days and lost about 6 points (75 - 69) over that period and subsequent “get back into it” workouts. Then that weekend I produced a lifetime best 20 minute TT power despite that number being fairly low to where it is in season for me. Even if you are more relatively fit now than you were a month ago, say a 275 FTP vs 250 prior, that number and trend line is based of your current threshold and not a base line that would see higher numbers the higher your threshold is. So you haven’t necessarily lost fitness, just your chronic training load has reduced.
Regarding the elevated HR that is likely due to the fact you really didn’t rest during that week off the bike, something these numbers do not take in to account, and you may be at an elevated level of personal stress or fatigue due to the circumstances. I highly doubt the days off the bike were restful and you probably had increased responsibilities and stresses off the bike and that can easily take a toll on your recovery and HR. You could also be getting sick, since you were likely in a hospital , my HR rises when I get sick and usually can predict it with such data. It could be several other outside factors than just your overall capacity or fitness during that workout. If you completed the intervals and the RPE was were you anticipated it to be then your fitness is fine, if it was extremely more difficult perceived then perhaps you did lose a little bit. I would stress over either of these two things for your relative fitness overall but I always recommend easing back in to it after time off like that.