I want to only marry Muslim girls
That's an interesting preference. Is that why you haven't gotten married yet?
Yes it's because I don't find anyone Muslim right now.
It is good to marry people with the same values as you and religion is a good way to judge what they believe. It will make the marriage work better if you marry people of the same religion.
I know but I can't find anyone with the same religion. I'm the only Muslim so it's hard for me to find a Muslim.
I'm sure you'll be able to find the right Muslim woman one day! It's great you are sticking to your religion and its values by waiting for the right person, even if it takes a while. Perhaps you can seek out Muslim communities to find them?