What should I do about her emotional walls? (very detailed!)

I have been officially with her for around a month and a half now. But we have been getting very close for around the past 6 months. She was saying things like "even before we got together I pictured us growing old together. I was just too scared to do anything."
Now recently... over the past week or so she hasn't really been herself towards me. About a week ago she came over my house and we laid in my bed, cuddled, and watched movies together. She stayed over late so she must have been enjoying herself. But... she didn't seem quite right.

I texted her the next morning (we text literally everyday) she texted me saying she felt bad for keeping me up so late because I had work. I told her I was fine, and I felt bad for her (she had to get up early too)

I said "I'm sorry for keeping you up :( You coulda gone home earlier"

she replied "No, I needed to stay late. This mood of mine is gonna be the death of me. :("

I replied "I was about to ask if you are okay :( You didn't really seem yourself last night. I know you were really tired, but still"

She said "Ya, I don't know what's wrong"

I said "I know how you feel. And maybe this is just me being stupid, but let me know if it's anything I am doing... If you want space or anything like that."

She replied with "It could just be my walls I put up. It's happened before and the poor kid was heartbroken, and now I feel bad. Where I get close to someone and then I shut down completely. Or it could be something completely different. Jess (her best friend) seems to think it's my walls. I don't ******* know. I'm just miserable all the time and it's no ones fault.
If any of that made sense"

"It's nothing you're doing or can do... It's just me being a miserable *****."
"Don't worry about it hun. I'll be fine."

after that I tried to ask her if it was anything I was doing to upset her. If there was anything different I could do. She reassured me and told me not to worry.
We haven't stopped texting every day, but things still don't seem quite right. Since then I have probably texted her telling her that I love her... and she just ignores it and goes on with the conversation. It feels terrible :(. She is also less happy to talk to me it seems. Less joking, smiley faces or exclamation points.
I have seen her twice since that happened first she initiated, then I did. Both time we saw each other things seemed to be going great, and the second time, when I said "I love you" as we were saying goodbye and hugging, she did say it back. Things seemed fine, she was just less playful and flirty (how she normally is)

I feel like she has walls because she was abused as a child and also got out of a horrible relationship about two years ago (a long time partner who she has a 2 year old child with)

What should I do??? I am really torn up over this. She would tell me stuff like she pictures us together forever... but now I am not so sure she is feeling this way. Should I try to talk to her about it again? Should I back off and see if she comes to me? Should I just act as if nothing is wrong? Should I tell her that I am really worried that I did something to upset her, and let her know that I would never do anything to hurt her? (try to reassure her)

Again... I am really upset about this... and have been ever since that conversation. Any advice would be greatly appreciated

Women have commitment issues too! If she keeps telling you it's not about anything you've done, believe her. Continuing to ask may just make her feel worse that she is amking you doubt yourself. It sounds like she's depressed, or dealing with something big. My best suggestion is to just carry on as you have been. Maybe be a bit more tender with her. Every now and then ask her if there's anything you can do to make her happier or make her life better. Don't ask if you've done things wrong, just ask if there's anything you can do to improve things for her.

If she doesn't start perking up in a few weeks, then I'd revisit the conversation. Say that you miss the connection you used to have with her and you'd really like to get back there again. Ask her if there's anything she might want to talk about, if getting out what's on her mind would help, and if there's anything you can do to reassure her.

All of that makes sense, and I appreciate the reply. Thanks!

But I am really worried that she is just 'going through the motions' and she doesn't have any feelings for me anymore :(
the fact that she doesn't text me back saying "I love you" really kills me. It breaks me heart. (I suppose she isnt the only one with the problems lol) Any other advice you could offer me would be great.... Its very hard for me to take a 'sit back and wait' approach, even if it may be the best choice. This girl is the love of my life! And I pictured myself growing old with her... and she did too, at least at one point :(. I just wish there was a surefire way to make sure everything is okay. And if not... I just wanna know so I can try to forget about her

Gahhh... :'( its really upsettting me. Any advice, even if its a "hang in there" would really help me out. Thanks again

How old are the two of you? I'm just curious.

It may very well be that she is confused right now and is trying to continue your relationship in hopes that things will become clearer. Not knowing her, it's impossible to say. If you're not comfortable with sitting back and waiting, maybe you can talk to her about some of the things you just mentioned. Tell her you're worried her feelings for you have faded and she is just going through the motions. That you'd like her to be able to open up to you and tell you what's going on in her head that has made her withdraw. Ask her questions about what is going on with her, but don't keep asking if you did something wrong. Tell her what you want and ask her what she wants. It very well may be that she doesn't know what she wants right now.

Aside from that, all I can say is good luck!