Confronting your friend:
If you don't want to keep your friend waiting or wondering, a meetup will become the solution. All you need to do is get yourself ready, and once you have done that, you can then select a place for the meetup. Coffee shops or tea houses are perfect places for a discussion like this as they are not very noisy. A public place is also suitable for such a situation because both of you will try to avoid getting too emotional or losing your cool. Moreover, you must avoid to get together for dinner or lunch, as the conversation may even end before the food arrives. Breaking up over a phone call can be an option, but it should never be done over text, as you may fail to express your feelings.
Before you actually meet your friend, you must decide as to what you need to say to him or her. You must also be try to be as direct as possible without hurting them unnecessarily. On the other hand, there are some situations in which you can't be straightforward. If you are doing so over the phone, you can refer to the following example:
You: "Hi. Are you free? I needed to talk to you about something."
Friend: "Yes, sure. Go on."
You: "The thing is that I have been feeling a bit pressurized recently, and I did not know how to bring it up. I wanted to arrange a meetup, but I don't think it would be appropriate considering the situation. Honestly, I feel that you always end up bringing me down. I'm sorry if this is unexpected, but I don't think we should continue talking."
No matter what anyone says, friendships do become toxic at times, and a full stop has to be put right away before it starts affecting your mental peace and even your mental health.