I've met a fantastic woman, and I don't want to mess it up

I'm a man in my 30s and I've met a great woman who ticks all the boxes, but I'm very nervous of getting deep into a relationship with her.

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I've been married before to a woman I thought was perfect, but as soon as she got the ring on her finger, she changed to the point where I barely recognised her. I suppose I'm worried about the same thing happening again and worry I'm a poor judge of character.

Everyone warned me about my ex at the time, but I couldn't see it. She was the most fun person I'd ever met and I got swept off my feet. Once we were married, though, she became selfish, flirted with other men in front of me, was rude to my friends and basically bossed me around all the time.