Is something wrong with me

I dont know I think something is wrong with me. I get so weird around guys I can’t put it into words. I’m a good conversationalist I’m not awkward and I can talk to them *as friends* but as soon I see signs that a guy wants anything more even just a makeup I retreat into a hole and I feel weird. But I hate it because sometimes it’s a hot guy and I would want to do something ‘more’ but then I get this feeling in my chest that makes me feel gross and i dont know what it is. I wish I could just go around hu with guys and strut with confidence but as soon as tried to flirt with me I get so awkward and i dont know what to do. Any advice ?