My girlfriend is very sensitive and it's starting to really push me away. Help?

Hi everyone. Thank you for taking the time to read and possibly help out. Here’s some basic info about me, after which I’ll give details about my relationship:

I’m 28, living in Southern California, and live a healthy lifestyle. My girlfriend is also 28, lives in Southern California but she lives about 2 hours away. We’ve been together for a year and almost one month. We see each other every weekend. Either I come up or she comes down. I come up more than she does since she drives an SUV and her gas is expensive and I drive a sedan. She’s also in school and is finishing in 3 months. During my unemployment I would come up sometimes more than once a week to see her and spend time with her.

The problem is that my girlfriend is very sensitive and at times insecure. She is a VERY nice girl with a kind heart. This all started about 6 months ago. We would never really get into any arguments or fights. Our first real argument was over the price for airfare. I was traveling last minute to Canada to see some family and she wanted to come. She asked how much tickets were and I said, “roughly” $1000. I didn’t think much of it because that’s what I was looking at. She said, “oh that’s too much…I won’ be able to afford that”

A couple days later she called me and asked, why I lied about the ticket price and if I wanted to go alone I should have just said so. I asked what she meant, because I didn’t lie. She tells me that she checked tickets and found some as cheap as $650. I told her those have multiple stops and are red-eye. She said that I lied and that my explanation doesn’t make sense. We went back and forth a lot until I had to seriously apologize like 4 times over a period of 2 days until she accepted my apology and let go of the issue. It turns out she very sensitive to HOW I say and WHAT I say to her. We had a couple more fights, all of which I had to learn to speak very calmly, not say ANYTHING that she would consider: controlling, aggressive, not nice, or condescending, or disrespectful. I agree with all of this, yet unfortunately, she would not play by her own rules. At times, she would say condescending things, manipulative and disrespectful things, and definitely not nice things. When I called her out on it, she would say I’m not being nice and that I’m picking at her…

Fast forward to last month, our one year anniversary. We are both not working and have barely any money to spend on going out. We decided to go to a friends’ NYE party and spend the whole day together, just doing things we love. We decided it’s about the memory and time with each other, not about gifts…

Everything seemed fine until a week after our anniversary (today) she tells me on the phone that she feels that I’m no longer putting any effort, nor am I emotionally there. She also was very upset about why I didn’t get her a card for our anniversary. I explained to her that we decided it’s about the memory and that we wouldn’t get any gifts. I also apologized and said that no matter, what I will get a card from now on since I see that it’s important to her. She didn’t accept my apology and started saying how I’m just not showing any effort. I have been driving 2 to 3 times more to see her than she has to see me, even though we are both unemployed. I tell her every time I see her how much I love her and how she is so amazing. I point out the little things she does, or accomplishes and how I’m proud of her and love her so much…
When she says I’m not showing effort, I tried to explain all this, as calmly as I could, since I’ve gotten pretty good at speaking without letting my emotions upset me. She starts to aggressively pick at my words, like “what do you mean by this” or, “I don’t understand why you are making excuses and saying that”. I get very annoyed when she refers to my explanations as excuses, implying that I’m trying to evade responsibility of something I have done. I tried to end the argument by saying, as nicely and calmly as I can, “I’m sorry I didn’t get you a card, I had a wonderful time and it was very memorable, but I will remember to get a card no matter what we’re doing next time.”

She responds with, “How am I supposed to take that?! That’s not even a real apology, you don’t even mean it!” I lose my patients at this point and tell her I need to get off the phone because after apologizing as genuinely as I can, I can’t think of anything else to say to her. She then starts to get upset and says that I do this every time, I get upset with her and start to not be nice…She says I need to take time and learn to nicely apologize.

I don’t know what to do. I haven’t talked to her since we hung up. I feel as though she’s never happy with what I do, when I apologize and keep my cool, she RARELY accepts it. I feel when we argue, she’s so defensive it doesn’t matter what I say or how I say it, she will find something wrong with it. It’s crazy because I’m being as nice as I can, not raising my voice, calmly and genuinely stating that I’m sorry, and yet she makes me feel like I’m some crazy aggressive person…

I don’t know if I can take this. It’s happened too many times and I feel as though I’ve tried a lot to show her how much I love her and be as nice as I can be, yet she’s always finding something wrong. We’re considering moving in with each other when she finishes school in April, and perhaps even getting engaged. I’m having doubts because she’s just very sensitive and insecure, so at times, no matter what I say or how I say it, I hurt her. All the nice things I’ve done or said in the past go out the window and in her eyes all of a sudden I’m this aggressive angry person talking down to her. But I’m totally not, I’m calm, (Very calm for someone in an argument) and nice, yet she still says I’m not…It’s really bothering me.

For those wondering. She has issues with her dad about the way he would treat her mom. We’re both aware of this and she has done some counseling to grow past her issues. Our problem is very much the fact that she expects me to be a certain way, which she is not herself, and when I am, as much as I can be, it’s not good enough.

Any advice?