Shift Issues

Hello,
I’m new to this forum but not forums in general lol. I have searched high and low to try and find this exact issue I’m having with my 05 Sportsman 500. I have read that the idle has to be just right to be able to shift these beasts. so here goes. I only have H-N-R-L (L is off to the side). I can switch into H and sometimes the engine will shut off (idle is lower than it was but still around 1000 rpm it was at 1200) I start it back up continue riding and now to go from H to R it acts like it slams into gear and or grinds going in. Hard to pull or push into H or R and sometimes hard to find N because it goes straight to H or R. and now it gets better…when I put the wheeler in L (when I can find it) it will not come back out of L, I don’t want to use full force as fear of breaking something. I shut the machine off and still gives me a little trouble but it comes out of L and I can use the other gears now but they still act the same. My father and I tried adjusting the rods but we were on the trail and didn’t have the book with us. I do still need to adjust the rods slightly but was looking for more info before I dug head first into this. and also I’m in the process of getting the gas tank repaired so it is currently out of commission for the time being. Any help would be appreciated and I can give more info if needed.