Here's some tough love sweetheart. This isn't going to be easy to read.

Your problem has nothing to do with codependency. Codependency would be that you rely on him for food, for shelter, for livelihood. Your problem has to do with your self-worth, which you have ultimately pegged everything that you are and everything that life can offer on a 24 year old who, from what it sounds like, still trying to figure himself out.

You are 18, you are an incredibly young girl who seems to have invested in her first real thing out in the real world. Have you ever stopped yourself and asked who you were? What you had to offer? Who you want to be? That person is who you need to build, you need to answer those questions so you don't end up clinging to someone to provide you an identity. It is both lazy and self-destructive to your future. You will never have a really healthy relationship with anyone if you are continuously going to try to identify as them. It is good to relate, but it is tremendously toxic and self-destructive to identify.

You have a lot of work to do. You shouldn't be wasting precious time and energy on someone who is not there. If he wants to be with you, he'll come for you. Life has a way of delivering us what we want when we really deserve and need it, and not demanding it like children. You need to go out and discover who you are, WHAT you are, without the presence of someone else dictating or for you to adopt because you can't do it yourself.

It will be hard and it will feel like you are going through madness. But it will be worth it. Establishing who you are not only will never give you this sense of worthlessness again, but it will do nothing but give you people who you can relate to and connect with, and a love that you are deserving of.

Good luck.