mixed emotions

I currently work two IC jobs, work full-time hours some wks and others not.  I really enjoy my work and luckily I do make good money.  I'm here all the time for my two teenage kids and have been an MT for over 10 yrs, so have been home with the kids since they were toddlers.  Recently took a pay cut from one of my jobs and haven't received a raise from that job for several years now.  Because of the uncertainty of the MT field and marriage issues, I've decided to start looking for a regular full-time job not in the MT field, where I will have a regular schedule and benefits.  I have an interview Tuesday and I am really nervous and have mixed feelings about the whole thing.  I really wish that the MT field was more stable and I could actually continue to advance financially, but that's not happening.  I know that financially it would be best for me to get out and find a different kind of work.  The job I am interviewing for averages out to be about the same per hour, but annually I would be making more and will have benefits, holiday pay, sick pay, etc. - none of which I have now as an IC.  I haven't worked in an office for about 12 years and the thought of having to get up and out of the house every morning and then sit in an office for 8 hours, not being here for the kids, etc., etc., is really stressing me out.  I keep telling myself that this is something I really should do to help secure my future but the thought of doing this makes me feel nauseous.  I'm sure there must be others out there in this same type of situation.  How did you calm yourself about returning to a regular work place and dealing with the changes that will have to be made as far as the kids go?  Of course, I have to get through the interview first and get the job, but all these thoughts are going through my mind about all the adjustments/changes that are going to happen.  Any input from others in a similar situation appreciated.