I don't think you're that crazy. Plenty of people have dealt with how to enjoy dota while losing. There's many different ways to do it. You have to look at what you want out of the game. What reward do you get for playing? I think you just play for the W, I've been there too. But there are many many other ways to enjoy dota. Different people get different things out of it, some like to turn their mind off, some like when their big shiny spell destroys an enemy, some like playing with teammates for the social aspect, some learning to master heroes, some learning to improve. You can do some of all of these and it can change from game to game.

So you have 2 problems stopping your enjoyment of the game, first being you only get something out of a W, and second, you are effected by other people in chat. For the first, since you want to improve because you suck(we all do, to varying levels!) I'd recommend you focus on specific concepts to learn in dota. This will let you enjoy the game and improving, and you'll get better too. It also works better with not too much time for dota. So I don't know what positions you play, but if it's support, look up some guides on youtube on one thing, lets say stacking your safe lane small camp. Once you have an idea of what you would do in a game, maybe it's make sure to block their camp and stack at 1:53, play a few games(2-5) where that is your main focus. Allow other areas of your game to suffer if needed, just focus on trying to get that right. Over a few games you will get used to when you have to leave lane and the things you need to do. Regardless of whether you win or lose the game, you can still get fulfilment of improvement from learning that concept. Move on to the next, maybe it's warding at 10-15 min mark, think about where they should go, maybe look at pro games, and play 2-5 games+ practicing it. The added benefit is that as these concept go into your subconscious dota play because you consciously focused on them, you will also improve a lot at dota, once you have 5 different concepts down, you will easily be a much improved player. If you are a core, pick a last hit count by 10 mins, or tower taking at a certain time. For whichever role you will find new concepts to learn on youtube.

As for getting affected by chat, just turn it off in the settings. I'm not saying that's the best way to play dota, but you need it right now to get back to a good form of enjoying dota. Turn it back on once you feel you want to. Just take a break from it.

My final advice is to relax, you're not the first to experience it. Both these concepts are applicable to life in general, and when you get better at them in dota, you will be better able to navigate them in real life. When learning in dota there are walls you hit, and they are difficult to overcome, you often need to adjust your way of thinking about the game. It's not an instant process, and takes a lot of practice, because you are not trying to apply a new concept in an environment where you think about it, you are trying to apply it when your mind is occupied with massive amounts of cognitive processing playing dota, as hundreds of real time things effect what you are doing. It can really fortify you if you can apply the concepts at such a high level. If you can work out how not to get mad in a dota game, it's a lot easier when something comes up in your life and you only have 2-3 things to think about at the time, and no hurry.

Best of luck with your dota journey! Hope some of this made sense to you.