What Do I Believe?

So, the past few weeks, this question has come up A LOT: can someone lose their salvation? This topic has come up in different ways & it's frustrating me. You see, I have gone to a church for the past seven and a half years that believes in once saved, always saved. However, now I go to a university that believes that a person can lose their salvation.

What do I believe you ask? I DON'T KNOW. That's why it is so frustrating to me. I can so easily see both sides. What I have been taught by my pastor and multiple youth pastors makes so much sense to me on how a person cannot lose their salvation. But then you come across the issue of "that person was saved at age 12, but now they say they don't believe in God"--does that mean that they weren't really saved? On the other hand, you have the whole you can lose your salvation idea. Would God really reject someone who believes in them but hasn't been living for Him? My best friend made a point that they don't ask for forgiveness for their sins, but their are "small" sins I make daily that I do without realizing it and I don't ask for forgiveness, so what's the difference? In God's eyes, a sin is a sin...there is no small sin nor are their big sins.

So what's the answer? Is it once saved, always saved? Or is it that a person can lose their salvation? I'm trying so hard to come up with what I believe on this issue instead of basing it off what my church believes or what my university & some of my closest friends believe, which is hard. It's not only hard, but it is EXTREMELY frustrating because when the subject gets brought up, I stay silent. I don't like to talk about stuff I'm not sure about, and this is one topic that has me so confused.