Quoting

"One of your closest friends is suddenly turning into a different person -- their typical level-headed behavior is gone, and suddenly they're off being wild and wacky. Why they are acting this way is a total mystery to you, but it might have to stay that way. Ask all the questions you want, but if they don't want to answer to you, they don't have to. Respect their boundaries and give them some space for now. They will come to you if they need your help."

"A frustrating friendship is causing you to wonder what you ever saw in this person. People change over time, and unfortunately they don't always grow in the same direction. Accept who this person is becoming, but don't keep them in your life if they make you feel bad or bring out your insecurities. Friendships are elective relationships, they do not always have to be lifelong commitments. There is nothing wrong with moving on so you both can be happy."