Friend problem am i over reacting?

[Jessica]

My friend is on my case about going to the gym. I tell her all the time that I'm busy and tired from being busy maybe another day. (I do have a gym membership to plante fitness as well as she). She does not understand that I have to deal with family finding a job to help support my family (I'm not a teen mom. I'm talking about my own mother father and sisters) and school and I have and insomnia. I lost it today. She made a dumb comment over facebook towards me and I lost it.
I said to her everything I have to do in my busy life she says that's not hectic. Yet all she does is now go to the gym sit on she phone go on face book and gets ssi checks while I am trying to get a job go to school and take care of my sibblings. Am I just over reacting cuz she has been making these comments all week none stop and I'm tired of it. she is a good friend of mine if your wondering.