You will find purpose once you find what you truly want out of life. It may not be constant adventure at all. It might just be something you haven't thought of before. Right now you are focusing on what is lacking in your life, but not on what you DO have in your life. It's all about making the best with what you have. Find the opportunities in your life and pursue them. Try new things.
Also remember that in the end, it's your attitude towards life and what you focus on that matters. If you have a positive attitude and focus on positive things, you will have a happy, positive life. If you search for meaning, you will find it.