What do you do when your mom turns into a miserable person?  Is there anything you can do?

My mom has reached a point in her life where nothing seems to make her happy.  She travels from job to job and is always seeking something that will make her happy, and the truth is that nothing does.  I know that she has wanted to change careers or fields for a long time, and yet she seems to be stuck.  She isn't at an age where it is easy to break into a new career.  She has been in the auto industry for her entire adult life, and it seems that she has no joy in her job at all anymore.  She has had 4 different jobs in the last 4 years...the most recent only last 6 months.  Then she moved again.  At each job she finds fault with the management, or the processes, or something.

She started her new(est) job 2 weeks ago, and already seems very depressed and not excited about it.  When questioned, my sister and I get "it's ok so far", in a really dull, underinflated sort of tone.  She sounds like she hates it, but doesn't want to admit it.

She and my dad move from house to house constantly, and both seem constantly unhappy and upset.  'They have gotten to the point where they literally have no friends, because they have moved so many times and lost touch with any new acquaintances that might become friends, and their old friends from younger days have just faded away.  The two couples they were closest with...one died so the wife moved back to Missouri, and the other split up with his longtime girlfriend and so she is in Mexico and he is still around, but hard to round up, and regardless, lives many hours away from where they are now.  My mom never seems to make any friends at all, and so they only have friends that are ok with my dad....but he has lost his two close friends and never leaves the house to meet new people.

They don't attend a church of any kind, and are very much isolated.  They seem to have no faith in God at all, and I don't even think my dad believes in God.

I don't know how to help.  Phonecalls are so difficult because all they ever do is complain.  They move from one topic to the next, and from one complaint to the next.  My dad drinks sometimes and that is even more difficult because he just becomes more obnoxious.  My mom is currently living in a camper trailer during the week because they haven't fully relocated to their newest town yet....so my sister and I don't know where or what she is spending her time doing...we are afraid of what is happening in their lives, and they won't make any kind of change to better themselves or their circumstance.  They seem to be chasing around in circles and never looking for a real way out.  I don't understand and honestly, they have tired me out.  I don't know what to say...positive phonecalls always go down the drain until I finally hang up, feeling empty and exhausted.  They have a way of just making you feel guilty for enjoying any part of life, and unless you are miserable alongside them, they don't have much to say.  They don't call me at all....I've called them regularly but they haven't called my number in over a month.  It hurts my feelings, and I worry and pray for them, but really...what can I do?  She was on my mind more today, probably because Mother's Day is coming up.

It's sad.