It isn't possible to do now, but I used to play a classical instrument in my free time. It isn't possible to do now, but I used to play a classical instrument in my free time.

I don't (practice) anymore, but I used to play a classical instrument in my free time.

It isn't possible to do now, but I used to play a classical instrument in my free time, though I'm not able to do so right now. I used to play a classical instrument in my free time, though I'm not able to do so right now.

"I'm not able to" sounds more natural than "It isn't possible to do" in this sentence.

Every lunch time, I practiced anthe oboe that, which is a kindtype of woodwind instrument. Every lunch time, I practiced the oboe, which is a type of woodwind instrument.

Every day at lunch time, I practiced anthe oboe that is (a kind of woodwind instrument). Every day at lunchtime, I practiced the oboe (a kind of woodwind instrument).

Everyday at lunch time, I practiced an oboe that, which is a kind of woodwind instrument. Everyday at lunch time, I practiced an oboe, which is a kind of woodwind instrument.

DuringWhile/Through/By playing music, even though I couldn't play well, I could reduce my stress. While/Through/By playing music, even though I couldn't play well, I could reduce my stress.

DuringI could reduce my stress while playing music, even though I couldn't play well, I could reduce my stress. I could reduce my stress while playing music, even though I couldn't play well.

Reorganized this sentence to sound more natural.

During playing music eEven though I couldn't play well, I could reduce my stress whenever I played music. Even though I couldn't play well, I could reduce my stress whenever I played music.

Because of COVID-19, the practice room is now blockshut/closed, as a result, I haven't practiced it for 2 years. Because of COVID-19, the practice room is now shut/closed, as a result, I haven't practiced it for 2 years.

Because of COVID-19, the practice room is now blocked, and as a result, I haven't practiced it for 2 years. Because of COVID-19, the practice room is now blocked, and as a result I haven't practiced for 2 years.

Because of COVID-19, the practice room is now blocked, and as a result, I haven't practiced it for 2 years. Because of COVID-19, the practice room is now blocked, and as a result, I haven't practiced it for 2 years.

I don't want to forget how to play, so I hope the pandemic situation comes to an end soon. I don't want to forget how to play, so I hope the pandemic situation comes to an end soon.

Or simpler, 'so I hope the pandemic ends soon.'

I don't want to forget how to play, so I hope the pandemic situation comes to an end soon. I don't want to forget how to play, so I hope the pandemic comes to an end soon.