(Help) Sometimes super socially easy going, others super socially awkward

Sometimes I’m super chill, funny and know what to say all the time but other days I’m super awkward and don’t even know what to say about simple stuff at conversations. I’ve noticed that when I’m not awkward everyone loves being around me and approaches me so I wish I could be like that all the time. But it’s as if I couldn’t do anything to help not going serious and silent and then I feel super sad and useless because obviously people notice a change in my mood and don’t treat me the same. It’s probably that something triggers me and I don’t seem to notice. Tonight I’m going to another social event so please, if someone knows some tips I could use asap when I feel like I’m going awkward to be able to stop it on time, tell me 🙁 I’ve started drinking a lot at parties to cope with it and I don’t want to enter dangerous territory so I’d love to know healthy ways. Thanks!