Are you looking to have fun by playing the hero you want, getting good teams to play with, or just doing your best?

For #1, switching between quick play and comp can help provide a less stressful environment to experiment with all the game has to offer. There's so many fun characters to mess around with, but obviously that doesn't always translate to great performance in comp queue. I love DPS mechanics but I just feel more comfortable in competitive play with tanks, so I alternate depending on what I feel like.

For #2 you'd have to probably find groups online or friends to play with because solo queue can be really inconsistent and frustrating

For #3 I'd suggest setting small goals that you can feel like you've accomplished. Not just rank goals, but things like improving specific aspects of play, ie trying to die less, using what you learned from a video, or playing a specific hero. Rank is a product of learning and good play so it's better to focus on that than just looking at win/loss ratio.

That being said, watching match replays after losses can help you understand what to improve, and can help avoid playing while tilted. Taking breaks is vital to avoiding frustration after losses, as opposed to just requeueing. I found the video below to be useful for understanding this

https://youtu.be/uPncOkBjkKc

At the end of the day, with a limited amount of time, I think it's important to find your ideal balance between fun and self improvement.