advice?

Em

i’m a major introvert so being around people can absolutely drain me mentally. one of my friends will only ever really reach out to me if they want to have long intelligent conversations which i just can’t handle if my social battery is drained. is there a way to tell them that i can’t handle these frequent lengthy conversations? i don’t want to cut them off as a friend but i can’t keep pushing myself beyond my limits either. i feel really bad because i know they don’t really have any other friends to talk to but this has been affecting my mental health to keep putting everyone else before myself.