Why does this always happen?

Hi everyone I was just curious if maybe you guys could help since Google isn’t giving me much of an answer (or I just don’t understand the answer I was given) but every time I drink anything other than a heavily mixed drink I throw up, the mere drop of alcohol comes right back up…. I don’t drink much only just kind of started (25 f) so I’m not really sure why it’s happening? I didn’t drink when I was younger either.. just looking for maybe a reasoning or a way to make it not happen as much so I can actually enjoy going out with friends TIA!