Is it normal for my cousin to block me after i told her i love her?

Im a 30 year old guy and I have a 20 year old girl cousin with whom Ive been in love with for 4 years. We would hardly see each other growing up and even now only see each other at family events which is about once or twice a year.
When she was 16 I told her in a facebook message that she is a treasure with a kind heart. She did not respond in my favor and said that she just wanted things to go back to the way they were before I said that, so I complied and left her in peace.
Now she is 20 years old and has grown into an absolute bombshell beauty from head to toe, with a slight feisty sexual behavior, and still with that kind heart. And heres the thing, I am a good looking, fit and strong-looking guy myself and every time we see each other there is a palpable sexual lustful chemistry that plays out. I constantly catch her staring at me and I cant keep my eyes off her. She always hovers towards my vicinity to be close to me no matter where we are. When she gets close I feel my knees weaken and just being in the same room with her I get short of breath and extremely extremely aroused, close to climaxing on the spot. I saw her last month and at one point, I was leaned back against a wall and she stood about 5 feet in front of me and facing me. Without even realizing it I starting rubbing my torso from abs to chest with my left hand, up and down, because she was making me so horny (no other girl has ever made me feel this way, so powerfully). She stayed standing there watching me touch myself. There were other cousins around. When I saw that she didnt go away, I got off the wall and slowly walked towards her, then around her until my chest was facing her back, and she stayed there letting me get closer to her. I was about to blow softly on the back of her neck but someone came to talk to me.
So after all that I caved in and told her in another facebook message that I love her, and that Im gonna love her all my life. She responded by saying "well I tried to help you get over it but its clearly not working". Then I just went all out and told her "dont you realize the way you look at me? dont you realize your body language? Nobody would have to know, its nobodys business". And then she blocked me.
So I was wondering if I actually scared her off, or if she just didnt like that I was making assumptions about her and wanted to get back at me by blocking me. Is it normal for a girl to react this way to a guy when he talks to her like that? I most definitely would not have sent her that message if I wasnt damn sure that she wanted me too.