I'm not schizophrenic and I'm not wandering, but I know what it's like to be dependent and to need other people to justify eating and breathing. I've been in rough relationships. I am not sure really what advice there is to give; I am not coping well with what I have and barely get by - but I do get by. I have, at least, gotten this far.
When it comes to falling into bad relationships, all I can really tell you is that we can pick who we live for, and I don't believe it has to be with someone who will take us in and fuck us. When we're codependent like that, it is a pretty common course of events to be taken advantage of, as the desperate often are. Entering into relationships like that is usually asking for something to go wrong.
Probably somebody has told you that before, and my advice is obvious to see and difficult to realize. Probably none of this is helpful. I don't really know. I know that nobody told me, and have had to learn the hard way that it's better to become close with someone because you trust them, rather than just trusting them because you want to become close.
It's very hard to be alone; it's like dying of poison. But toxic relationships are eponymously poisonous too. I try to live for many people. More than once I have stopped myself from killing myself by imagining, one by one, all of the people who my death would affect. The major and the minor, the people who would only pretend to care and the people who would be on suicide watch themselves. That sort of makes me feel like I'm living for lots of people - a whole spectrum of reasons to live. At least, if you care about any of them, which I haven't always.
After one relationship turned particularly bad, and I couldn't sustain myself anymore, I moved in with my family, and they became my main reason to live. We aren't particularly close; people are often surprised at how distant we all are from each other. Nevertheless, they are my people, and they have always come to help me when I fall, which is very often. Relationships are necessary to almost everybody. Most people aren't really equipped to be alone. But there are a lot of kinds of relationships, and they can be what a desperate person needs, too. I hope there was something worth thinking about in here; good luck.