Don't worry about duolingo. Just think of it as another tool. I use memrise too. For sure it's no substitute for speaking to others but it's surprising how some things stick.
The other day i said without thinking "braf ar rhai" meaning ok for some.
Remember ssiw teaches you a great conversational framework. To add to it you need to grow your vocab etc.
I'm considering organising a theme based minibwtcamp on cooking, where people who attend need to teach others a recipe. People would need to learn cooking terms and use them. Not worked out exactly how to do this but the point is to use new vocab in context.