When you’re 18, emotions run pretty strong. Your highs feel incredibly high, but your lows feel incredibly low. It’s all a normal part of emotionally maturing. I think we need more info about your relationship to pass any sort of judgment, though. Can you pinpoint why you react negatively or positively to him at different times? What specifically do you love about him? Do your personalities mesh, does he treat you well, do you have similar goals and ambitions, etc.? What’s behind the moments when you feel happy and more in love with him? And, more importantly, what makes you not want to be in the room with him? Is it your feelings changing or is it something he’s doing? If he’s disrespecting or abusing you, whether emotionally, verbally, or physically, that’s not normal and you shouldn’t be in the room with him. If you’re annoyed by him, ask what annoys you- is it something specific he’s doing, his personality, how he treats you, or something else? 

It’s normal in a relationship to not feel lovey dovey all the time- relationships take work and loving someone is often a choice more than a feeling. But if you’re frequently unhappy being with him, it may be a good idea to reevaluate your relationship and either fix an underlying problem or remove yourself from the relationship. And remember, what’s normal for you may not be normal for someone else and that’s ok (so long as there’s no abuse happening). Just make sure your normal is something you want and make sure the relationship is generally something that brings you happiness- there’s a difference between happy relationships with tough moments and bad relationships with good moments. It’s easy to just remember the good times, but make sure you reflect on the good and bad when deciding how to proceed with your relationship.