Maybe it is because now you are more aware of your own mistakes? The more you study the more you know, but speaking is an active skill that needs more than just the knowledge. Think about it as reading a book about swimming. You may know the right way to swim, but you still haven't adquired the skill to actually swim. You need to get inside the water and practice there to actually be able to swim. But if you overthink about what you read in the book when you are in the water then you may drown. In the water the main priority is survival, it doesn't have to be pretty it just have to be effective. When you go out of the water you can analize your mistakes, practice the right way mentally and then get in the water again and challenge yourself. I think the same happens with learning to speak: you can practice in a controled environment, but when you are in the water (when you are actually speaking to someone) the priority isn't to remember all the knowledge and follow the book, you focus on staying afloat, you focus on effective communication even if it is not pretty or it is full of mistakes, you keep the conversation alive, and that's all that matters. Later you can analize alone or with a tutor or with your conversation partner what were your biggest mistakes and you practice the right way many times and then you go into the water again. (These are just my thoughts on the matter. I think the more we know what should be the right thing, the more scared we get of making mistakes, and so we get huge mental blocks. We just need to let go of any expectation and keep moving. We eventually will make a breakthrough and see the pay-off of all our efforts).
For me a very enjoyable way to practice speaking without the fear of making huge mistakes and getting blocked is by acting k-drama dialogues. It's a lot of fun!
I think you are right. I set high expectations for myself and, as you said, I need to let go of them and just enjoy the fact that I'm actually able to communicate. A year ago I wouldn't have seen myself having conversations beyond the point of 'how are you?' and 'what are you doing today?' . Thank you very much for you message, it was actually eye-opening that I need to go easy on myself and in the end everything will fall into place. I might try drama dialogues in the future, it does sound like a lot of fun. ^_^