Hitting higher velocity pitching

Let's get the background out of the way first - I'm 25 and pretty athletic. Played lacrosse in college, yada yada. This year, I'm playing summer league with the boys and it's tons of fun. That being said, I haven't played since I was 15 or so, and I'm having a hard time getting used to higher velo pitching. When I'm in the cage taking BP I'm able to really effectively square the ball up and drive it, but in game I feel like it's been tough getting timing down. I think part of it is rushing my swing and lifting my head, so I've worked on this with the classic "bite the collar of your shirt" drill. I guess my question here is this - what can I do by myself in order to better prepare for higher velocity pitchers? I do a lot of tee work, side toss, watching video of my swing, etc., but it's tough to find guys to throw 80 to me when we're all older and working or busy all the time. Thanks for any advice.