It took me a long time before I got things right my first time. They say "practise makes perfect". Keep at it and you will get the hang of it. I cut the rust out of a car and I must have done 3 or 4 goes on each patch panel. The car itself was pretty much a waste of time but I learnt the hard way.(I think it was the best way get it right!!)
The patch panel you did looks pretty good for first time in my opinion.