I think I am heartbroken

So....it's been a rough week for me.  It's definitely the hardest week I've experienced as a Mother.  I feel defeated, burned out, and sad.  I have cried a lot this week.  I never cry....it's just not in me!  However, the water works have been turned on full blast lately.  Today, we went to The Little Gym which we've done since the triplets were 4 months old.  They are in the "Beasts" class.  I've noticed over the past few weeks, they cry, throw fits, and generally seem unhappy.  I decided to move them back down to "Birds."  I see other 20 month olds who are talking, running, hopping, jumping, and hanging from the bars as most 20 month olds do.  Well, 1 of mine will talk a little and 2 will run, but Austin can't do any of those skills.  He has just started walking, and he's really careful about it.  Today, I saw a little boy push him down over and over again.  My heart broke for poor Austin.  I didn't say anything to the Mom.  I didn't try to rescue Austin.  I just watched.  He finally gave up, put his head down on the mat, and burst out into tears.  The rest of the time he just wanted me to hold him.  Sometimes I think people are so cruel and heartless to people who are slow, handicapped, or different.  I just can't deal with mean people right now.  I just want to take Austin somewhere for the next few months, get him caught up, and come back with a faster little guy.  I want to fix him, and I can't.  The only thing I can do is love him.....it's very hard to be a Mom of a preemie.