Feeling the pressure

You get that guilty feeling at work as if you are not pulling your weight?  I joined the group early last year and then went on maternity in Sept.  Somewhat new in the group and then sort of not.  I work where men are the majority.   A lot of them single and/or young eager to prove themselves.  Stepping up and moving the bar.  Able to pull late nights and milk the benefits of free dinners and car service.  As well as go for drinks and smooch with the managers and bosses. And still be able to get in before I can.  I feel guilty leaving on the dot and dashing out.  I go home thinking about work and sometimes even dream about work!  How scary is that?  I get a guilty consious when I take days off.  Then when I return from missing out work a couple of days I get this terrible feeling.  I stay late when I can but I just can't help but wonder if just all me.  Is it possible to have it all?? Are there other moms feeling the same? Yes, I want it all. I guess you can if you can handle it.  Some people tell me to take it easy and stay as longest as I can.  Sometimes I feel like i need to look for something that doesn't require staying late and meeting deadlines. Then there is another part of me that wants give it the best.