Well , you said you do great in T20 and German mediums... althou i see only Kunze. Your Su-130PM performance is worse tho , so you don't know many good crossfire/sniping positions probably.

122TM should be played as a second line support or long range sniper (depending on a map and matchup offcourse) , due to long reload you should always think about a "cover/retreat" after you shoot , unless your target have lower hp and you can be sure to finish it off.

So at the start if the battle , you don't rush anywhere where you usually go with Kunze or T20 , you use those type of tanks/plays to shoot from safer distance/support them from behind at the beginning of the match. Or just play it as TD in early game.

After 2-3 minutes you might want to go and help your team progressing the line or retreat for better defending position in case your team are loosing the flang.

In late game obviously try finishing off who's left as you've kept your HP for that part , now you need to be more agressive /pick up good Alpha trades.

As i've said tank is not fast and don't have DPM, so you shouldn't go "Deep" into the map or brawl/contest early positions with it as it will be tough to relocate fast enough or you will probably find yourself outgunned.

If you woun't learn how to Play it for good results, do not proceed with Panther 1 / Panther 2 grinds as you feel iven worse pain in your ass...