“Would I still be saved?” is probably not the right question to be asking. If you’re a believer, you can be confident that you are saved by God’s grace. It’s then a matter of persevering in faith and obedience through your whole life.
So before I answer your question I just want to ask if you are this confident in your own salvation? Because you can be! This confidence does not come from our effort (“If I am good enough then I’ll be saved!”) but comes from the fact that there is nothing I can do to be saved and therefore depend wholly on Jesus for my future. This faith in Jesus gives us confidence because we know that not only can God save us through Jesus but that he has. Is this the sort of faith you have in Jesus? Is this the basis on which you say you are a Christian? Come back to me if you ave questions about this and have a look at http://www.christianity.net.au/god.
The Christian life then becomes not a question of being good enough for God but being the person God wants you to be - confidently living your life in obedience to Jesus. So your question should be “what is the obedient thing for me to do in this situation?”
Now at this point I need to be quite frank with you - dating a non-christian and living with a woman you are not married to (And by this I mean having sex with) is NOT living obediently under Christ. The Bible teaches that Christian are free to marry whoever they wish, but they ought to be believers (1 Corinthians 7:39). So if we shouldn’t marry non-Christians, then, we shouldn’t go out with them either. It also is not right for you to be living together without being married, because we are meant to reserve sex for our marriage partner. The Bible teaches us to flee from sexual immorality (1 Corinthians 6:18), and this includes all sex outside marriage.
I hope you don’t mind me being quite frank with you, but really you must confess these sins to God and ask him to forgive you. And you also need to confess to your girlfriend that you’ve been doing the wrong thing by her as well. By living with her, you will have sent a message to her that Jesus is not really all that important to you. It will seem to her that she is more important to you than Jesus is, and that’s unhelpful for her.
Normally I would say you should not marry a non-Christian (1 Corinthians 7:39), but now that you are living together, it is more complicated. My advice is that you should tell her that if you get married, she has to understand that you are going to be serious about Jesus - you will be at church regularly, you will give away money to church and to those in need, and that you will want to raise your children as Christians. (It also means you’ll be a really good husband too!!, Ephesians 5:22-33.) If she agrees to that, then get married, and pray for her every day that she will come to know the Lord. If she doesn’t want to get married, then that is her choice - you should let her go.
If she agrees to get married, then schedule the wedding soon, and one of you move back to your parents while you wait. That might sound like a big cost, but it will make your honeymoon much more special.
Thank you for asking a question which affects you so much. It shows that Jesus is important to you. I have prayed for you that you will do what is right, though it is not easy.