If you've been in a one sided friendship it can wear you out. Actually, suck the life out of you. Bustle lists these situations as Red Flags you should watch out for. I've had some of these friendships and these really make sense to me.
1. You're the only one making plans.
2. You're always bending over backwards for them.
3. They treat you like a therapist.
4. You're exhausted when they're around
5. They don't value your time.
6. They hide things.
If this sounds like someone you know, RUN!