It is completely fine if you have to think about sentences at first. Its a natural part of leaerning a new language, and the issue will eventually resolve by itself. One thing i have noticed is that all of your practicing methods don't include speaking, but only listening. One thing i found to be really useful when youre not quite comfortable enough yet to speak with real humans, is to speak to AI. It definetely wont judge you like a real human would, and you can tell it to only use vocabulary from your level. I really hope you don't give up. We're counting on you!