Is it love, lust or just a crush?

I know it seems stupid, not being able to identify your own emotions but when in doubt, ask random strangers, right? So, I have a friend, we wouldn't be what would be considered your typical "close" friends, there's a few years between us, we sort of travel in different circles, it doesn't stop us from talking to each other and texting quite a bit. I've known her for years, we've only been talking for the last 3 though and we've only been closeish for the last 6 months or so, we sort of drifted when she left for college but we started talking more when I told her that I'm a lesbian, at which stage I found out that she was too, ever since, I've gotten to know her a lot better. I've always had a crush on her, well, for a very long time at least and it sort of intensified when we started talking but since we've gotten a bit closer, I feel like I've started doing more than "liking" her. It's like, when I spend time with her, I just feel content? She has an effect on me that no one else does, she calms me and relaxes me, she gets me to act like myself, completely. When I see her smile, I practically melt and when I'M the one who makes her smile or laugh, I can't describe it, I feel like I could run on that emotion for the rest of my life. I honestly think she's perfect, even her "bad habits" which might annoy others, I find endearing. I want to spend time with her and when I can't, I get so pissed off. My mind always seems to stray to her. I think she's gorgeous, sexy, funny, cute, smart, beautiful, everything and when she insults herself, in my head I feel like screaming out to her and telling her that she's the single most amazing person I know and that changing herself in any matter would be completely insane. I don't, obviously. It kills me that she doesn't see in herself what I see. I don't think I've ever had more interesting conversations with anyone in my life, I could listen to her for hours. My infatuation with her doesn't stop us from messing around with each other though, we're constantly making fun of the other and we're always trying to find a way to top the other in witty remarks. It's fun. SHE'S fun. Ever since I've started feeling this way about her, I can't really think of any other girls, even when I'm with them, it doesn't stop the nagging voice in the back of my head saying that I'll never like this girl as much as her and I know no girl deserves to put up with that. I know she'll never feel this way about me, I'm aware of that fact and it hurts, a lot but I don't care what girl she's with as long as they treat her right and make her happy. Honestly, I don't know how someone could treat her badly but they do and when that happens, I'll admit, a part of me wants to attack them for making her so sad. I'd never risk what I have with her by telling her, I know it would just mean she'd distance herself from me but I still want to know, am I actually falling in love with her? I've been with other girls and it's never felt this way, I get more of a jolt from brushing skin with her than I do when I kiss other girls. I've never really believed that love exists and especially not this early on in life but lately, I've been doubting that. Before this, I thought that the way I was feeling with other girls was great but now, it seems dull in comparison, that may sound bad but it's true. Any thoughts would be much appreciated, as you may have guessed, she doesn't exactly cause me to think straight, so maybe someone can do it for me. Thanks.