<human>: Can you summarize the given text in a few sentences?

Hi reddit.

First of all, thanks for taking the time to click bc I could use some listening ears and friendly advice.

My gf and I have been dating for a little over a year and a half. She's just fucking incredible, and my god still gives me butterflies. However, we could not be more different. The same reasons that brought us together are starting to cause problems now. She's type A, I'm a "free spirit". She works with data entry and logistics, I'm an artist. You get the idea. 

For a long while, I was sure I wanted to marry her. I mean, just the idea of it gave me this wonderfully grounded high- that I finally found the one. But over the last 4 or 5 months, we've struggled with the basic compatibility. We have talked about our visions for the future, and they differ quite greatly. Mainly, her being certain she wants kids.. and me not so sure. I'm even feeling that marriage might not be something I want (just because it seems like it'd take away freedom.. not to seek out others, just.. selfish freedom). Though, I didn't have great examples as my parents divorced when I was 2. My Dad's a playboy and my Mom's been married 3 times. Her's have been together for 30+ years.

ANYWAY, I'm just not sure anymore that she's the one. But, I am still in love with her. I still want to spend ALL my time with her. I still appreciate how unwaveringly and passionately she loves me. 

Is this imbalance normal?  Is it unfair for me to feel this way and stay in the relationship? 
She knows she wants to spend her life with me. No doubts. 

She is aware of how I feel, btw.
<bot>: My gf knows she wants to spend her life with me. I used to feel the same but have recently developed doubts and it's ripping me apart inside bc I'm still in love with her