Ouch! The truth is that if you are parenting well, your children will not always be pleased with you because you are thwarting their will. They don't realize that in the process, you might be keeping them safe, guiding them to becoming a better human being, or teaching a valuable life skill. They might not be able to see that until they have their own children...15 or 20 or more years from now.
Need a backbone? If you cave in every time one your kids accuses you of being a mean parent, then you might meed an external backbone in the form of a friend who is roughly on the same parenting game plan. This is someone you can trust who can help you talk through in advance how to handle those situations that are chronic and whom you can call if you feel yourself turning into jello.
Love and Logic classes, CDs, and DVDs can help with "jello-y" backbones because they give you more tools for your parenting toolbox. No one should parent alone... we all need help.