Frustrating point in language learning

[smmg]

I've reached a point with my Irish where i feel like I need to get rid of everything I know in it and start again from scratch. Does anyone else ever feel like this? I remember a couple of years ago i felt like this with Welsh, but I don't remember what I did to get over it. I guess this is just how I feel once I get to the B1 stage in language-learning...? I feel like there's so much I know and I keep forgetting it all. There's so many grammatical things and idioms that I keep learning and keep forgetting, and it all feels hopelessly complicated in my head. Frustrating. I don't think it helps that I've been feeling low in regards to language-learning in general recently.