You could try saying, “I know I agreed to do this, but I realize I need some help.” Then sit back quietly and see what happens.
If the response isn’t what you’d wanted and needed, that’s ok. Just take a deep breath, then restate your needs – clearly and without anger. My experience is that when others are in the habit of expecting that you’ll “just do it,” it may take some time, patience, and clear communication before you’ve altered those expectations.
And if you can calmly stick it out until your message gets across, you may find that you’ve won the respect of your family, colleagues, friends – and that you are feeling less stressed and angry. If you’ve done your best, and people still aren’t paying attention, this might be a good time to reevaluate your relationships.