Should get married when no longer feel about sex with his girlfriend

Every time I took the initiative, she was elusive, and this situation lasted for more than a year.

I and I have known each other for more than 4 years, I am 28 years old, I am 25 years old. We seldom have conflicts because we both understand each other, generally everything is fine except for that. We are not far apart but the frequency of relationships is very low, about once a month, sometimes more than 2 months. Sometimes I have to handle myself to solve the physiological problem. Now I really don't feel about that to you anymore. We plan to get married in the near future but I'm wondering, will a marriage that is not happy about sex be strong? Hope everybody consulting. Thank you!

Independence