I am horrified that people here are encouraging you to leave home. You are not being abused, you're not in danger, and your physical well being is being looked after.
I'm not triviliasing your feelings but a lot of 16 year old feel as you do, whether they live with mum and dad, one parent or in a step family like yours.
You not being allowed to things is a sure sign that your parents worry about you and want to keep you safe. It is hard being a parent, worried sick when children are late home or doing things maybe they shouldn't be.
What you need to do is boring, hard work but effectual. You act in a grown up, responsible way, get on with your school work and show your parents that you are growing up. I bet not all your friends are being given free reign, even when they are bragging about fabby things they've been doing. You have no idea how worried a parent gets.
Negotiate privileges such as going to the cinema, ice skating, bowling, hanging out with friends and make sure you are home when you say you will. Keep in contact with your mum when you are out - a quick text saying you are waiting for the bus home will go a very long way.
16 can be a horrid time - not quite adult but certainly not a child. Lots of hormones and emotions.
You will have a much brighter future if you can stick it out at home, growing up at a steady pace with the security home life gives you. Talk to your mum - show her this post. It's a great starting point.