That's when I realized the importance of keeping healthy, so. I started to change my daily routine and go hiking. That's when I realized the importance of keeping healthy. I started to change my daily routine and go hiking.

That's when I realized the importance of keepstaying healthy, so I started to change my daily routine and got into hiking. That's when I realized the importance of staying healthy, so I started to change my daily routine and got into hiking.

"staying healthy" is better "got into hiking" = became interested in hiking and started doing it as a habit

That's when I realized the importance of keeping myself healthy, so I started to change my daily routine and I started hiking. That's when I realized the importance of keeping myself healthy, so I started to change my daily routine and I started hiking.

That's when I realized the importance of keeping healthy, so I started to change my daily routine and started hiking. That's when I realized the importance of keeping healthy, so I started to change my daily routine and started hiking.

My New Year resolved to upgrad's Resolution was to improve my daily habits and exercise habits. My New Year's Resolution was to improve my daily habits and exercise habits.

"upgrade" normally means "get rid of something tangible and replace it with something better" — it's normally use with physical objects (I upgraded my computer's GPU) "improve" just means "make better" and it's much more flexible / you can "improve" pretty much anything

My New Year's resolvedution was to upgrade my daily habits and exercise habitsmore. My New Year's resolution was to upgrade my daily habits and exercise more.

saying "habits" twice feels strange when they're related, so i changed this so you only say it once

My New Year resolvedution was to upgrade my daily habits and exercise habits. My New Year resolution was to upgrade my daily habits and exercise.

My New Year's resolved to upgradution is to streamline my daily habits and exercise habitsroutine. My New Year's resolution is to streamline my daily habits and exercise routine.

My New Year resolved to upgradution to improve my daily habits and exercise habitsmore. My New Year resolution to improve my daily habits and exercise more.

It's a little difficult, but I am trying my best to practicstay consistent / get it done. It's a little difficult, but I am trying my best to stay consistent / get it done.

Your original sentence was OK, but I changed the verb so it is closer to "尽力去做"

MORE SUCCINCTLY: It's a little difficult, but I am trying my best to practice. MORE SUCCINCTLY: It's a little difficult, but I am trying my best.

Keeping Healthy Keeping Healthy

ALSO POSSIBLE: Keeping Healthy ALSO POSSIBLE: Keeping Healthy

NOTE: There is a nuance between "Keep Healthy" and "Keeping Healthy." (I could explain it in Japanese or Chinese, but do not know what your native language. I wish that information was displayed on this website's format.)

I became a little weak after my first COVID-19 infection at the end of 2022. I became a little weak after my first COVID-19 infection at the end of 2022.

This is grammatically OK, but I would personally say: I became a little weak after ___ getting infected with COVID-19 for the first time ___ at the end of 2022

It was easy for me to get aAll of last year, I easily caught colds or the flu and often feelt tired last year. All of last year, I easily caught colds or the flu and often felt tired.

Since you talked about time at the end of sentence 1, it emphasizes the contrast / makes it a bit easier to read if you also talk about time in the beginning of sentence 2. With "cold" we normally say "catch" not "get"

It was easy for me to getcatch a cold or the flu and feel tired last year. It was easy for me to catch a cold or the flu and feel tired last year.

fixed expressions "catch a cold" and "the flu"

It was easy for me to get a cold or flu andor feel tired lasthat year. It was easy for me to get a cold or flu or feel tired that year.

ILast year it was easy for me to get a cold or flu and feel tired last year. Last year it was easy for me to get a cold or flu and feel tired.

It was easy for me to get a cold or fluALSO POSSIBLE: I got a lot of colds and feelt tired last year. ALSO POSSIBLE: I got a lot of colds and felt tired last year.