I love my wife of 20 years very much. We have four teenage children, one has serious mental health issues. I’ve been having a two-year affair - I don't know how it started, or why it continues - though she makes me feel good, and free.      
      My wife caught me several months ago; I told her it’s over and tried to break it off. But it isn't. I’m trying to understand why I’m so weak. I don't want to be this man, yet daily I lie to my wife. How can I end this and recommit to my marriage?
      - In Angst

You’re living in a false sense of “freedom” from the realities of a partly imperfect life. Now, look in the mirror. You’ll soon be living in a far worse mess when your wife inevitably discovers the lies and throws you out.   
      You’ll then have all the responsibilities you now try to escape, PLUS having hurt and angered your wife AND children, who may never forgive you.    
      The ability to recommit starts now. Change what you can – your cell phone number, your pattern of free time when you see the other woman, and, most important, STOP LYING.    
      Ask for your wife’s help. Get counselling together; show her you need her strength in order to find your own again. Do it, or risk losing all self-respect, along with everything else’s.

My father left my mother 10 years ago to marry someone else. I've tried to have a relationship with my step-mom who insists we respect her and include her in the family.    
         My mother sees her as the "enemy" so whenever there are special occasions we apologetically explain that my mother’s uncomfortable with her there, so we can't invite her.     
      She'll say things like "your mother should get over it, I have a right to be there too.” But I'd rather have my mother at special events than my step-mother. She doesn't have any real interest in my brother, sister and me.  She always brings up testy subjects and if we don't agree with her, she gets upset.     
      We want to see our father, but whenever she's there it becomes very tense. She continues to be bitter and make us uncomfortable. She can be very nice too, but I feel she's just playing a part.     
      My father insists she's a wonderful lady and we've tried to get to know her and spend time with them. He’s told her to back off the testy issues, but she seems to be getting worse.    
       My sister refuses to acknowledge his wife so Dad visits her. But he makes me feel guilty so I kept visiting his home. I no longer want to … I always leave feeling drained and sad.
      - What to Do?

Grow up. You and your siblings have excluded this woman enough to arouse her bitterness and hurt, yet won’t allow yourselves to see her other than through your mother’s eyes.    
      Though it’s understandable that she can’t attend events with your mother present (she’s persisted in bitterness, too) you and your father could’ve arranged alternate or duplicate events for both “sides,” just as many divorced families do.    
      Example: Christmas dinner with Mom, brunch with Dad and Step-Mom; a birthday celebration at Mom’s, another at one of your houses including Dad and spouse.
      She keeps your Dad happy. Why he and your Mom separated is their story, not yours, and it’s 10 years ago. Get on with what’s needed today.

My administrative job is painfully boring and doesn't use my two-year-old university degree or any thinking. I’m losing my skills plus my potential. I constantly ask for work or to help others, but often there's nothing to do.    
      I've been looking elsewhere for three months, with no responses though my resume/cover letter is quite strong. I don't have any experience in the field that I want to work in (law/social justice). I’m also afraid of being laid off (my superior is aware that I’d like to be busier).
      - Bored to Tears

Attend an evening courses, workshops, and volunteer in your spare time in the field you want. A resume without anything related to your interest, gives you no advantage as a job candidate.    
      Once you make yourself busy in advancing your knowledge and skills towards a specific goal, you’ll be far less bored in a secure job that pays your way.