Well, I am trying to learn finger-picking, too. And I'm doing a little strumming with a pick. When I tried strumming with my finger and thumb nails it just sounded like mud. So, I don't do it now. When I want a chord instead of a note when finger picking, I just pluck the top three strings with my fingers and one of the bass notes with my thumb. It's not a strum and it doesn't sound exactly like the guy on the record, but it's the right chord at the right time and that's good enough for me.
Remember, you've got ONE MONTH of playing and the guys on the records started, improved, became intermediate, went pro, got a contract, and THEN recorded what you're trying to mimic. Thinking you can strum like a pro on a record after a month of playing is like thinking you can do open heart surgery because you dissected a frog in biology lab. Be patient, do your best, add some more patience, and keep practicing. I guarantee you those guys that sound so good on your records sounded like crud at the end of their first month of playing.
Good luck, keep a smile on your face, and if it gets too frustrating for you just set the guitar aside for a bit until you're calm again. Pick it back up. You can't play well if you're all stressed out about how it's sounding. If you're the sort of person who gets stressed over progress, maybe record yourself once a month. At the end of a month, listen to how you sounded last month. You'll hear the improvement if you're practicing. But my advice would be to remember that you're doing this for fun and not to get stressed out over something that's supposed to be fun. Just an attitude improvement can improve your playing and it will definitely allow you to progress more rapidly.
All the best,
Granted B chord amnesty by King of the Mutants (Long live the king).
If it comes from the heart and you add a few beers... it'll be awesome! - Mekidsmom
When in doubt ... hats. - B.G. Dude