It's great to have people you care about, supporting you and making you happy.
But also to be able to stand on your own two feet, and not to be dependent on others to be content. It's not as easy as it sounds, no. Like anything it takes effort and time to start seeing results and get to the point where you want to be.
But really, to an extent its about being yourself, wholly and uncompromised. Don't let others dictate how you live your life, make decisions for you, decide what you can or cannot do or make you change yourself to please them. Being selfish is bad, but being confident and to know what you want, now that's good.
Ask yourself, what do I want? What do I want to do with my life? What are you passionate about? What makes you happy? What do you believe in? The key to everything is "you". You are the most important part, and should always have priority over everything else. There's nothing more important than your wellbeing.
I found this article, which I thought was fitting, check it out if you want;
http://www.limitless365.com/2013/01/29/how-to-stop-living-for-someone-else-and-start-living-for-yourself/
Finally, I would like to address your statement "I don't see a life without him". Remember the fact, that you lived before you met him, and you will afterwards too.
“The only person who can pull me down is myself, and I'm not going to let myself pull me down anymore.”