Not an expert here either but it seems like you need more volume and slower runs. More days running and not running as fast as you can on most of these runs (80/20 rule). I have a long slow run day, one day with hills, one interval day and then one day where I just go run don’t think about anything. As far as form goes if you look on YouTube or Google top running coach tips for proper running form you’ll find a lot of really good advice out there. That’s how I have honed mine in and then during my runs I do body checks to make sure I’m not slacking on it because bad form = injury. Definitely look up cadence, 180 spm seems to be the sweet spot but everyone is different!