How do I get the motivation to start being healthy again?

I (28, F) have been through some health problems this year and had to have surgery in the beginning of October. This was a big deal to me since it was my first time admitted into a hospital. Lots of anxiety and stress but the procedure was successful. Post op wasn’t painful but it took a toll on my mental health. I had to sit back and do nothing for a month.

Before that, I was pretty healthy. Exercised almost every day and woke up early. I feel like I had some time to think this past month and wasn’t what I expected. I started noticing I didn’t actually like my job, had no big goals in life. Comparing myself to others all day wasn’t good. I noticed everyone happy and accomplishing things while I regretted my work and life choices. Watching tv all day and doing nothing was a struggle. As I got out of post op, I found myself fighting to get my balance back. Started smoking again (had been smoke free for 1 year), couldn’t find the motivation to eat healthy or exercise.

Now I just wake up every day, have my cigarette, eat lunch and try to work without getting completely exhausted. I’m finding it hard to be productive like I was before. There’s a lot to do at my job, I just feel like I can’t focus and get things done. It’s so different than before and I don’t know how to turn things around, start exercising again and waking up early to enjoy a new day. Feels like day one all over again. How can I stop thinking about it and actually doing something?