Are you sure you two had the same conversation when you discussed spending your lives together? Did you bring the topic up or did he? Did he actively contribute to the future-talk or did you say a bunch of shit while he went "um okay" and "sure I don't see why not" etc?

Guys generally don't plan very far ahead. We weren't planning out wedding day when we were 5, but a lot of girls force us into those conversations where all we can really do us go "uhh ya I guess I can come with you to a wedding 8 months from now, girl I've been dating for a month" and then when you leave we go "fuck that was awkward, she's practically picking out our baby names, I thought we were just dating."

Or he might just be busy this week and your paranoia is interpreting everything negatively to feed into itself (your Reticular Activation System in action).

Give it another week before you panic and quit calling him for a couple days so you don't look like a psycho clingy stalker to him. When you DO talk to him, for god's sake don't cry lol

Girl, I would run and I would run fast.

One thing I've learned is that a woman should be wary of a man who offers such serious commitment quickly. If a man speaks of planning his life with you within the first few months of a relationship, you should be wary.

Men who come on super hot and heavy are often telling you what you want to hear in order to get what they want from you. A man who is really serious about you wouldn't bring up such discussions early on. Those kind of talks would typically freak a woman out.

I've also noticed that men sometimes offer commitment up to see how eager a woman is to grab it. It seems counter-intuitive, but I've known some men who test women by seeing how eager they are to jump into a relationship, any relationship. What they would like to happen is to have the woman not agree to the commitment or try to apply the brakes. In a way, it let's him know that she doesn't want to be in a relationship for the sake of the relationship. She wants to be in the relationship because the man has proven himself. He wants the woman to be choosy. Your guy had no way of proving himself in only 4 months. You probably shouldn't have been so eager to take his offers of commitment, at that point in the relationship.

What probably happened is that your guy promised you the moon and stars, you agreed to those terms, and it freaked him out. He really had no intention of offering you those things, at that point in your relationship. You should have been spooked by those professions of commitment, but you weren't. When he realized that you expected him to do what he said he would, he knew he wouldn't and bolted.