I don't even like to use the term "self-care." I mean, why should taking care of yourself have its own special term when taking care of others isn't classified in the same way? Would you go around saying Parent-care, or children-care, spouse-care or dog-care when talking about all the other people you may be taking care of in life? Using the term self-care makes it seem like it's a special thing and therefore makes it feel self-indulgent. But the truth is, without caring for yourself, there's no possible way to care for everyone else around you. You can't pour from an empty cup.
And this is where many, myself included, fall short. We fail to understand that even though we may be a Mom/Wife/Daughter/whatever, we are still Living, Breathing, Beings. We still need to be cared for, just like we care for all the other living things and people around us. Well, I'm hear to tell you - GET OVER YOURSELF and LOSE THE GUILT. There should be zero guilt associated with caring for yourself. Period.
And if others around you are making you feel guilty (more likely than not, they aren't, but rather it's all in your own head and the things/thoughts you are repeating to yourself about what you should be doing instead of caring for yourself) - tell them/yourself to get over it too. The convo may go something like this: "If I don't take this time to shower/wash my hair/do my workout/shave my legs/whatever, then you can be sure that dinner is going to be missing that special amount of vitamin Love and the drycleaning won't be in the closet and half the mortgage won't be paid because I won't be performing at work" etc. The truth is, self-care, if you want to call it that, is not a self-indulgence, it is an act of self-respect.
Taking care of yourself is telling yourself and the world around you that you care enough about yourself, that you have enough respect for yourself, to understand that you are a breathing, living, human that needs the same things that all other breathing and living things need - love, attention and care. In whatever form feels right for you, make sure you pay attention to what you need. It's the only way to fill your own cup so that you can continue rocking life, the way you were meant to.