If I had to guess, I would say the reason your pancakes charred on the edge is either because you're not getting the flour coated in fat, or because you're not letting your batter rest. I'll run through both issues briefly here.
Fat. So, all the major pancake mix producers use a process that coats each individual flour grain with fat, usually something similar to vegetable shortening. The better pancake recipes include actually cutting in shortening which is delicious but also very time consuming and difficult to get right given how little you use of it. A short cut that can help you is to simply add a small splash of cooking oil or butter to your batter, about a tablespoon or so. Mix it well, but don't overdo it. And I see you're already doing that so what I can offer is try to add the butter when it's not entirely melted and add it first to your flour almost as though you were making a roux. There's really no substitute for shortening if you're aiming for perfection but then that stuff isn't great for you either.
Resting. There's not much to say about this. It's simply a good idea to let your batter rest for 5 to 10 minutes so that your flour has a chance to really hydrate. This is doubly true if you take my advice about adding oil! What I think is happening to your cakes is that water is pooling in your batter because you've either not mixed it thoroughly enough, not let it rest to properly absorb, or both. So when you go to pour out your batter onto the pan the loose water with less flour in it runs to the sides of your cake in thin streams that burn fast while the rest of your cake is still cooking through.
About the only other tip I can give you is to use medium low heat. Good pancakes take a little time to get going if you want them to fluff up. Your patience will be rewarded! Also, I know it's cheating, but there's no shame in using bisquick. I admire you for trying to perfect your home made mix and encourage you to keep trying, but honestly aside from the superior fat-coating technique, there's nothing they're doing that you wouldn't do in your own kitchen and their cakes come out great!
Thank you very much for taking your time and breaking some things down for me! Concerning the first part, the recipe I used called for a little bit of butter in the batter which I did add :) I guess it wasn't the issue now (some people recommended to skip the butter in the batter)! As to the second part, you are very right, I didn't let my batter rest at all, I had no idea it was a thing when it comes to pancakes.
I've never used Bisquick haha, I just like making everything from scratch, it is time consuming, but I have plenty of time now that I quit my job haha
Thank you very much again for helping me out with this! Have a great weekend!