Somebody once told me that love is putting somebody else's happiness before your own. If the two of you break up and he/she eventually starts to date somebody else, you'll be happy for him/her rather than spiteful, because you want them to be happy. That's the gist of it, at least--there's a lot of gray area area on the matter (ie. terms of breakup, terms of relationship with ex's new significant other, etc.). This resonated with me when I heard it, and that's now what I consider to be love. This doesn't apply to being in love, though. I don't know the difference between that and infatuation.
I considered myself to be in love with my current boyfriend for a few weeks, maybe a month or so. About a week or two ago I started to question my feelings, and now I'm not really sure if I am anymore. This could be due to stress (both of us have been on edge due to factors external to our relationship) and spending practically every waking hour that we're not at school and/or work together. I've also felt a bit depressed lately and have a hard time getting out of bed most mornings. Or, maybe it's because we've been dating for what feels like a really long time now and the initial excitement has worn off. I wouldn't know from experience, I've never been in a serious relationship such as this before. I know that I love him and care about his happiness, and that I enjoy his companionship. But lately I haven't felt as affectionate toward him, and my sex drive/sexual attraction to him has declined. I used to love having sex with him because of the emotional and mental aspects of the act and we have pretty good sexual chemistry, but I've avoided it three nights in a row now. Is this normal? We've known one another for well over a year now through mutual friends, but we've only been dating for roughly 4.5 months, and speaking on a level that suggested we were interested in one another for roughly 5.5 months--not a long time.