Need HELP! Suddenly can't cover my HP? Please!



A while back I marked my T54 thanks to lots of help here. I was so proud and happy! Was consistently making maybe total of 4,000 combined damage per battle. Consistently kicking butt. Never less than 2,000. Felt like maybe I was starting to know what I was doing? Felt like there was room for further improvement in the cards. Felt good.

Bought a premium TD to replace the credits that I burned marking my T54. Played that for some time. Making good credits. Building my credits back up. All is well? No. It's a tragedy. Now, I'm a mess.

I got out my obj140 (was NEVER good with it) feeling confident and get crushed. So, I get back in my T54 and I'm getting crushed. wth? I'm lucky to cover my HP in my beloved favorite T54? Can't win a battle.

The best example is my last battle in El Halluf. I'm doomed wherever I turn. I shoot and get shot. Shoot and get shot. Where do I post my replay? No link on WOT that I can find? Need advice. I'm doomed. I'm open to suggestions that relate to the game, to the tactics, to philosophy. Anything. Please help.