I'm having problems connecting into games

Both yesterday and today, I have forced my team to remake because I never connected into the game. Not only that, but whenever I do connect, the game's already into the third minion wave and I find myself two levels behind my enemy.

Despite not connecting, the wheel in the top left corner that appears during the loading screen still spins, leaving me to believe that the game simply hasn't started yet. However once I load in I see that this is clearly not the case.

This used to never happen to me, but now occurs at least once a day, and I'm really starting to get sick of it, because I can barely even play the game anymore.

I play on a Mac, so maybe that has something to do with the problem, but my friend has the exact same model and has had it for the same amount of time however he loads into games just fine.

ALSO, in games mostly during the laning phase, my game just freezes, out of nowhere. Sometimes it only freezes for a second, other times for thirty. If anyone knows how to fix these problems please let me know.