Am I being too impulsive by wanting to break up?

I'll start out by saying i'm 13. I've been going out with this guy for about a month now, and it's been great. However, lately i havent been feeling as bubbly and happy inside as i usually do when i hang out with him. We dont go to the same school, so we only see each other on weekends. I just found out that he got me an engraved sterling silver necklace for Christmas that cost NINETY DOLLARS. I feel so guilty that i'm having second thoughts now. And he is TOTALLY in love with me and would NEVER do anything to hurt me. He tells me he loves me every single day, and its a bit overwhelming but sooo sweet. I'm just not feeling the same way anymore... am i being too hasty by wanting to end our relationship? should i just wait it out? Please help me.