Instead of dropping out or switching languages, just ask for a hint. Pick one of the suggested replies, learn from it, keep going.
This is especially useful in early stages of learning when your vocabulary is still catching up with your thoughts. You know the idea, you just do not have the words yet. Now you do not have to stop.
Every hint comes with a translation so you understand what you are choosing, not just copying. That is how you actually build vocabulary. Practice a language, get unstuck, stay in the conversation. Try it in chat.