Nothing is impossible, this is true, especially if God is involved.
However, it will be very difficult, especially between two completely different religions. Like you said, how do you raise your kids? Do you tell them about Allah or Jesus? Which holy book do you use, the Bible or the Koran? Which rules do you follow regarding lifestyle and such?
All of these questions will come up and create tension. For example, did you know that the Catholic church does not support artificial means of birth control? Did you know that they don’t support abortion or homosexual marriage? Did you know that Catholics beleive that the Eucharist IS the body, blood soul and divinity of Christ?
Make sure that you sit down and talk about these things and come to common ground about them. Try to find out as much about your future husband’s religion as you can and he should do the same.
BTW, I know a lot about Catholicism because I am a Catholic. I know that if my wife wasn’t Catholic, it would be very difficult when it came to issues of faith between us. In fact, she converted to Catholicism before we got married, not because of me but, because she looked into the religion and found that there was so much more for her in the Catholic church than the one she was going to.
A strong faith is what builds a relationship. Without faith, even a shared faith and understanding between two religions, there is no foundation. Pray together, even if you pray in different ways. Prayer gives us such graces, it helps us to discern right from wrong and to get God’s help when we need it. It also allows us to celebrate the good and the bad with him.
So I will say that yes, it can be done. It will be hard and there will be conflicts but, if God truly wants you to be together than nothing on this planet, nor in hell below can keep you apart as long as you have your eyes both focused on God.