Lack of excitement and love feeling

I have been seeing a beautiful Taiwanese girl for just over 5 months now. She is the kindest person I have ever met. She is vegetarian, hates any bloody scenes in movies and does not touch drugs. She is very passive. I think she is an amazing person, but, there is a problem....since we first met this relationship was originally only for fun. It then turned into bf & gf. About a week after we almost broke up because of me ( I was not feeling the love or excitement factor towards her). 5 months on and this brake up situation has happened about 4 times now. Originally I think it was from fear of commitment because of unseccesful relationships in the past. Later I realized that when I am around her I do not feel excited, or more alive. I keep feeling like there is something missing. I went away on holiday for 2 weeks in December and when I came back there was still no excitement when we saw each other. I am due to go to China for 4 months to work and I am confused on how I should handle this raltionship. On the one hand I have an amazing kind person, but on the other hand I have a weird gut feeling that this isn't right because I don't feel excitement or a "love" feeling that I have felt with gfs in the past. When I said I don't love her, she said she doesn't love me either, because how can someone love after 5 months? I understand that long term love is more than just excitement, but am I right in thinking that you need excitement in the beginning to keep the commitment? One side of me does not want to lose such a kind person, the other side wants to be free and travel the world solo etc.

Yes, you're correct. Chemistry is the glue and the initially most obvious prize that you work or fight so hard for (and the higher the chemical compatibility, the harder you work to keep it). Whilst you're busy doing that, attachment - courtesy of time and mutual pleasing repetition - starts to take hold. You then sense it, whereupon it becomes a case of, "but WHAT do I fancy?", and you start to 'road-test' them with the long term in mind. No chemistry? No glue. Too little incentive. You obviously need (to quote Adele) someone just like her *PLUS* bam!, kapow!, wow! chemistry. And regarding those two elements, who on earth said you *couldn't* have it all?