I want to improve my skin elasticity. Please recommend a good treatment.

I've been noticing my skin's elasticity declining since the beginning of the year, but as the end of the year approaches, my face looks dull and saggy. I'm scared of how much older I'll be next year. Up close, my skin feels like it's sagging, not to mention losing elasticity. Pillow marks and other indentations on my face don't go away easily. I even have mask pack marks ㅠㅠ My face is sagging, so what can I do to improve my skin's elasticity? I'm thinking about getting a skin booster treatment, but looking at my sagging face, I wonder if a face lift should come first. Could you recommend a treatment that would improve my skin's elasticity and even my facial contours?