Love in the workplace

I work at a YMCA so it’s just rooms with kids and staff after school. I work with someone who is 19 and I, 17. We started talking around October and it’s just not fun to me anymore. I lean more towards girls than boys and I struggle to keep feelings for boys when there’s a “relationship”. I’m not sure how to call things off because don’t want things to be uncomfortable at work. I haven’t felt the same for the past few weeks what should I do?