When you deal with anxiety the way you have been dealing with it, your subconscious eventually learns what's normal and stops sending you the panic signals. So for example you'll be sitting on the train and have a faint signal to observe and check your heart rate, but it's now a bit half-hearted(sic), and easily ignored.
Also, recovering from the infection will have a massive effect on your ability to cope with anxiety. Even now, if I get ill my anxiety hovers around in the background because your entire central nervous system is on alert. It never goes anywhere for me any more, but I can still sense it there, like a battle hardened Jedi