Hey there!
If you're having trouble knowing what you believe anymore, maybe you just need to spend some time away from people in good ole' fashioned nature. I know it sounds like a really stupid thing to suggest, but people tend to cloud us with doubts and baggage when we draw too heavily on them. Try some time alone, and definitely crack open a Bible under the shady trees to tackle the subjects you're having trouble with. Pray about your dilemmas in the loneliness of nature and... as stupid as I know this probably sounds right now... it will do you a world of good. Sometimes just being surrounded by God and his creation, but away from the crowds, is really the ticket. At least the quiet stillness of the situation will help to get you centered. The world may appear wise in it's own element (the one we live in). But that is not our world, not forever...
Also, if you're having trouble because God doesn't feel real to you anymore, maybe you need to ask yourself "Am I being real to God" rather than "Is God real to me." He isn't just out there, but he's right here, within your heart.
Ask in the stillness...
Trust me, you'll find out my friend.