We are often so set in our ways that we have difficulty to change. People are so used to you being a certain way that it makes it difficult to set new boundaries. But the whole point is for YOU to feel better about yourself, not for others to like you. YOU are not in a popularity contest, you are trying to change to make things better for YOU.
Stick to your point. Don't send out mixed messages. You can't establish a clear successful boundary if you send a mixed message, and MOST of all...don't apologize for your behavior. Ultimately the changes that you make is for YOURSELF and not for others. Don't feel guilty or embarrassed to set your boundaries. If you feel that you need change in your life, then listen to your inner voice. You can't continue to go forward in life if there are things that hold you back.
If you are frustrated and there are things that really bothers you, it is half logical that you have to say goodbye to certain things in your life.
Even the bible states in Matthew 18:8
If your hand or your foot causes you to fall into sin, cut it off and throw it away. It is better for you to enter life crippled or lame than to have two hands and two feet and be thrown into the eternal fire.
Why do you need emotional and Intellectual boundaries?
Have you ever been caught outside in the rain without an umbrella? If you don't make the necessary changes in your life to make YOU happy, then you leave yourself open to be affected by other people's words, and actions. Why would you keep on exposing yourself to something that might end up making you feel miserable. People have to adapt to your changes and you don't have to feel guilty or apologize for the change, just be respectful.
Make people aware of your boundaries
How would anyone know that you have made a change if you don't tell them? If someone does something that you don't like, be clear and tell them straight. I had a friend that used to touch me all the time. It made me feel violated and awkward. She used to come sit with me and held my hand the whole time while she spoke. How weird is that? I don't think she even realized that she did that but stopped when I told her.
Be consequent
People need to be aware of your boundaries. If they don't like the changes that you make, then perhaps it is time to re-evaluate your friendships. Ask yourself these questions;
Could I survive without this person in my life?
What does this friendship give me?
What do I get from this relationship?
If you can't find adequate answers, then get rid of the baggage.
I would rather have one good friend than ten others that don't give me their full attention or constantly criticize me because I am who I am.
STAND YOUR GROUND
If you made a decision to change, then stick to that decision. There is a specific reason why you made that decision. Do not slip or give it a second chance. The second you slip, someone will come in and do the same thing that they have always done and mess up everything again.