I am glad you are getting a benefit out of the tactics trainer. However, after looking at your last two losses, I believe you would benefit from some of the lessons on how to open the game. You lost both games to similar tactics made possible by the weakness of your opening. In both games you lost material because your bishop on c5 was rolled back by your opponent's queenside pawns.
I am not saying you should memorize lines but basic things like knights before bishops and not opening holes in your kingside (creating ways to pin pieces against your king) are important and not beyond the current level of your game.
In various forums, including but not limited to chess.com, I encounter a sentiment that's met with unhelpful advice -- beginners asking, "how do I 'stop blundering?'", met with "You'll blunder for the rest of your life; we all do."

I think what most beginners mean is "How do I stop giving away material with easy-to-spot tactics that are only a couple moves?" To which I answer, "By working with the tactics trainer."
When I first joined chess.com, I wasn't accustomed to playing with a clock, I didn't have good "chess vision", and I would give away material left and right and wonder how I could miss such obvious moves. My rating was below 800.
At the advice of some players in local clubs, I started making a habit of tactics puzzles. With 36 Rapid games under my belt and only a couple months of consistent play, I've reached 1050. People in my local club have told me that now it "feels like" I'm playing chess (you know, getting totally wrecked instead of getting epically wrecked), and I've "dramatically improved for such a short period in chess time." I'm inclined to agree with them.
A quote I read about Go puzzles is that they're like individual words of a foreign language - without the words, we can't think about how to structure our conversations. I am coming to feel like chess puzzles are the same way. My ability to perceive threats on the board, assess them, and try to make threats of my own has improved tremendously by regularly doing tactics, and I make moves accordingly. Those same club players have told me that strong tactics alone are enough to get to 1600+. I wouldn't be surprised.
Now that I feel like I can better feel the board, I have, for the first time, felt like looking over instructive games and other high-level material is productive. And don't get me wrong -- I'm still losing games in small tactical skirmishes. Most recently, I didn't identify that if my opponent took initiative in a small exchange, he could take my soon-to-be-en-prise-knight. I didn't shore up my little horsey with an available pawn, lost my knight, and lost the game.
So, while I think it might be time to learn a thing or two more about the game at large, I'm definitely not giving up the tactics trainer any time soon.
Oh, and P.S. -- if you're rated as low as I am, I've been told by pretty much every respectable player in our clubs (some former experts) to not even bother studying openings. I hear that it's pretty useless until you're 1600+. One player even said it's actively harmful. I mean, think about it - what are you doing memorizing lines if you're going to give away all the material after a few moves anyway?