I Pretend to Be Busier Than I Am to Avoid Social Plans

I often tell friends or coworkers I’m “swamped” or have “a ton going on” when they invite me to hang out, even when I’m not that busy. The truth is, I just prefer staying home, watching shows, or chilling by myself most of the time. I feel bad for lying, but saying “I’d rather be alone” feels too harsh or like I’d have to explain myself. It’s not that I don’t like them - it’s just that socializing can feel exhausting, and I need a lot of downtime. I worry I’m pushing people away, but I keep doing it. Anyone else do this, or am I the only one faking a packed schedule?