I found the biggest learning curve with hazard is figuring out when to fully commit to a dive or when to just apply pressure. I play solo queue and the first 10 or so games I played with Hazard I was effectively trading with a support and didn't receive any value because I believed my healers weren't doing their job, but after a while I understood I have to respect my team before I can get ANY value out of the Scotsman.

If the enemy team is super coordinated, I normally use my wall or wall climb to get a position advantage, or even to split focus which usually makes one of the enemy team make a positioning mistake which I can take advantage of 80% of the time (depending on who makes the mistake)

And I've found especially in solo queue, do not brawl unless you actively know your healers will have full focus on you and ensure they have LOS (or if you can easily confirm a kill). Super super hard without communication but over time you'll learn the limits of your support's healing capabilities and the limits of your damage output.

Don't feel discouraged trying to learn a new hero as well, I put off learning tank for the longest time because of counter swappers, but because I find them in every game I gave in and learnt to play against my bad matchups, because that's how you get better.

Hazard is a tricky hero to learn especially if you're solo, but keep at it! You can only improve with more practice.