Putting so much pressure on yourself seems really stressful. It's a wonderful thing to learn something new about yourself and be open to this experience of attraction to someone (even though it feels scary). You are safe, no one is demanding you tell them what your sexuality is, and honestly, it's nobody's business but your own. Take your time with this- you're in the process of learning who you are. This is a lifetime commitment, not something that you have to decide and can't change when you're 17.