Hi @
stuff. I'm going to respond to this from two different perspectives (professional and personal), not necessarily covering the same thing though.
Speaking as someone who has conducted interviews and hired new staff, a second interview is amazing. Most interviewers know after the first interview who they are seriously interested in hiring, one of the reasons for conducting a second interview (especially with a different person) is to confirm that the feeling they got from you in your interview is accurate. So congratulations on making it to round two. If you are feeling any stress about the second interview, I hope this tidbit helps to ease it a bit.
Coming from a personal standpoint addressing the 9-5 job, PTSD, and insomnia, for me it actually helped to have a set routine. The first few weeks were rough going, it took a lot of effort for me to get into the rhythm of things, but after that period, the consistency helped. I'm dealing with insomnia (and some fear of going to sleep) currently, part of the reason is starting up on medication again (side effect is insomnia), and part of it is from fear. Having a consistent time I go into work helps to adjust my sleeping pattern, sometimes I'm still incredibly exhausted going into work because I didn't sleep the night before, but my body is used to getting up at a certain time now, and going to sleep at a certain time. The consistent pattern helps correct my insomnia on it's own after a day or two.
Not saying this is how it is for everyone, but coming from a personal standpoint, that is how it went for me.