Way too much thinking. Try to just be. Why would you wake him up? Why not just tell your mil you're going home and she can relay the message when he gets up. Then, you've woken him up so why now tell him you'll walk? Sounds like you were upset and he responded upset because he doesn't understand why you're upset. He's now defensive.
Then you keep sending him him texts and messages. You haven't given him his space to deal with his emotions. You want him to deal with yours, NOW.
And why are you so upset you can't sleep? You slept on the couch. That tells him you're still mad at him. So he stays mad at you.
Find a way to let situations drop. First, find a way to be more independent. You want to go home, you go home. Don't expect him to reassure you that it's OK. Then, when both of you are upset, stop talking with each other until you're both in a calm space. You know that he won't react well when he's mad.
Have enough confidence in you and your relationship that you don't keep needing his reassurace that he cares, that he approves, etc. Be your own person first; then work together to find a way for you both to be comfortable with each other.
I urge you to get into counseling. You know you're needy. It's really hard to be in a relationship with a needy person. It feels like no matter what you do you can never do enough for that person. He knows something is wrong and he doesn't know how to fix it. Men are fixers. They frequently don't do well with lots of emotion. Get counseling to find out how to be more independent. Learn how to get some of your needs met elsewhere.
You have not described an immature man in this post. You've described a needy women seeking reassurance who isn't able to just let the first angry words go. There was a "scratch" (his angry retort) and you won't let it heal. You keep scratching at it making it hurt worse.
Both of you go to counseling if he'll go but if he won't you go. You do not have to feel this way. I would not leave until you are clear about how your thoughts and actions are a part of this situation. Look at this as an opportunity for you to grow and become a more secure person. Do not leave until you've tried working out ways in which the two of you can learn and grow together. You've invested these years and have a child together. Don't just throw it away until you've tried counseling and know for sure that you're not compatible. You have nothing to lose by working on making things better.