Lost husband taking care of his wife, kids, dogs, full-time job, and house

Hi everyone, just joined today and I am looking for a little guidance.  My wife was diagnosed with stage 3A breast cancer in October 2015.  She is 45 years old (now), has a terrible family history of other cancers, and is scared to death.  She has been through two rounds of AC/T chemo so far and the tumor has shrunk quite a bit we are told.  Last night she lost just about all of the hair on her head at once.  I, of course, was about 30 miles away at my accountant getting our taxes worked out.  My daughter was here with my wife and helped her in the shower.  My wife had a panic attack, my daughter got scared, and I walked into a nightmare.  

A little more history is in order.  My wife has suffered from chronic pain syndrome brought on by PTSD from a criminal sexual assault by a cousin about a year before we met.  She has been through nearly 5 years of therapy and has been on strong opioids to combat the pain.  Prior to her cancer diagnosis she was in the process of being weaned off the meds and this is not welcome news, obviously.  

All that to say that I have been taking care of things around here for quite some time.  We have 2 teenagers, three dogs, and two foster dogs.  I work full time and usually have a part-time job working overtime to get extra money, as my wife is unable to work.  Since the diagnosis I have brought her to every appointment, in Chicago, which is about 17 miles away from our home in the suburbs.  I rearrange my work schedule to accomodate this and FMLA is available so I won't be in danger of losing my job or benefits.

The chemo rounds have been rather uneventful, so far.  She has been tired and nauseous, but hasn't vomited and her appetite remains strong.  The hair loss, and anticpation of hair loss, has been devastating.  I couldn't care less if she has no hair, a crew cut, or a lion's mane.  I didn't fall in love and marry my wife because of her hair.  I have tried to be as comforting and reassuring as I can but I can't seem to find the right words.  I really wish I could take this cancer from her and put it in me, because I hate seeing her suffer,

I know things will probably get worse from here on out.  We have head coverings on order, the medical staff is really supportive, and I have a couple people I can talk to.  I wish I had the right answers when my wife feels so scared, helpless, and says she never weants to leave the house again.  I am trying to deal with my kids being upset and scared, maintain the house work, and still be productive and effective at work.  I am looking for ways to cope because I noticed I am not sleeping well, my appetite has decreased, and I go between sad and upset constantly.  I recently joined a band as their drummer, which is something I love to do, but I feel guilty leaving the house to practice and play gigs.  Any help would be greatly appreciated!