Do you ever feel really weary--like life is ping you by?

I am a mom of 4--my 8 year old has special needs,and the others are ages 12,13,and 16.I adore my kids and would do anything for them--and I feel a bit selfish for what I am about to say...but here goes--I spend SO much time caring for others that there really is no time left to care for me.Anyone out there who may feel that way too,how do you deal with it?!