Any pointers that might help both of us (read: me) improve?
I know you're going to hate this answer, but here it is nonetheless: Stop sparring. I'm serious. First of all, its dangerous if you don't know what you're doing. Second of all, you will only get worse, and it gets harder and harder to fix habits that are ingrained. YouTube is a perfect example of how awful you will get by sparring without an instructor helping you... it is littered with really terrible free fencing videos.
Second thing: If you can't find an instructor, then get some books. I highly recommend Christian Tobler's
Fighting with the German Longsword. It will give you a broad overview of the Liechtenauer tradition of fencing. If you want a more immediate solution, here's a very generalized article I wrote a couple years ago:
http://www.myarmoury.com/feature_arms_gls.htmlIt isn't perfect, and it is only a "teaser" article, but it can at least give you a taste of some of the core actions of the system.
And then you need to start drilling the actions with your partner. Not just once or twice, but over and over and over, until it becomes part of your muscle memory, so that when you see "X" attack you automatically respond with "Y" counterattack without thinking. And after it become second nature, then *maybe* it is time to start pressure testing it by doing free fencing.
But I'm serious: Without an instructor, any free fencing you do is likely to result in you using techniques that work to "get the point" as opposed to actually using realistic martial techniques, let alone the risk of injury. The analogy I like to use is learning a foreign language: At some point, yes, you need to start conversing with another person. But if all you've done is memorized a few words, and you never learn the theory, the structure, how to form tenses, etc, and if the only person you ever talk to is equally ignorant of the language and says, "Let's just learn as we go," then all you'll get good at is learning to speak gibberish. Which is exactly what will happen to your sword technique.
Understand that I'm not saying this to give you a hard time: I'm saying it because its what I see constantly, and then I see people online acting like experts just because they've spent the last few years beating up their friends with sticks in the back yard without ever having learned a single thing about an actual martial art.