I am having an issue with chord progression, strumming, and keeping everything together cohesively when I play. When I'm "noodling" with the guitar it seems I can change chords fairly decent - however, when it comes time to play along with a song everything falls apart. Either I change chords seamlessly, strum seamlessly, but never both. Also, as soon as I start to play at normal speeds I tighten up my muscles, press the string too hard, and generally fall apart. Any suggestions on drills? Or anything I can do? I've quit guitar a few times because of similar issues - and at 40 years old I'm determined to stick with it. Thanls for any help!