I make up fake plans when people ask what I'm doing for the weekend so they think I have a life
Why do you make up fake plans when people ask what you're doing for the weekend?
My friends plan to do stuff with me only to realize at the last moment they have something more important to do.
I'm sorry that your friends don't spend enough time with you. I understand it must be embarrassing to not to have any plans of your own.
I really want to just go out and get a drink or something. I just want to get out of the house.
That might be the first step to having things to plan on your own. Start making plans for yourself for real and follow through with them. Then when they ask you if you have something to do and you happen to not, they might ask you to tag along, or if you do have plans you won't be lying to them.