Feelings are a very important part of life. We all have emotions and the Bible speaks a lot about things such as love and joy. In fact a book in the Bible (Song of Songs) is almost entirely given to the feeling of being ‘in love’.
However, emotions should not be the primary thing that drives us. It is the Bible that we must trust and obey, not our feelings. If we doubt God’s love for us, it doesn’t mean that he doesn’t love us. The same is true in relationships.
It is normal to have doubts from time-to-time. I have found that my biggest fear and doubt in a relationship and pursuing a relationship is trust. Trust is a huge part of any relationship. Once we have been hurt, it's very hard for those walls to be broken. Eventually we have to fully let go of the walls we have built and allow ourselves to be hurt by someone we love. This requires 100% of ourselves trusting that the person we are with is who they say they are and trust that they will not hurt us. The thing to do is analyze why you have doubts. There may be legitimate reasons or they may turn out to have no basis in reality. The Bible says more about the character of people than the ins-and-outs of a relationship. So Christians should be looking for people who are growing as Christians, people they can encourage and who will encourage them. That will mean they are submitting to God and saying ‘no’ to sin.
As to being ‘in love’ or just ‘love’, I don’t think there is much of a difference, except to say that what the world often means by ‘in love’ is infatuation and lust whereas the Bible speaks of love as selfless active care and concern for another’s wellbeing - ‘this is love, not that we have loved God but that he loved us and sent his Son to be the atoning sacrifice for our sins’. 1 John 4:10. In other words, love is more about sacrifice and service than a warm feeling.
I have loved before and I have been “in love”, however, when I look back on past relationships, I see the missing pieces. I do not see a love that was more about sacrifice and service than feelings and contentment. I can be “fine” with anyone, but I want to be crazy, happy, selfless, and so in love that I can’t help but smile constantly. I know no man is perfect and I know that I will be disappointed, but I also know something good is worth the fight. I don’t want a perfect man. I want the perfect man for me :)