It's mumbling season

Finally, I'm done with one of the 2 papers I was supposed to write. Almost broke my back; despite having started on it over a week or more ago, I ended up without a wink of sleep, writing all night before the deadline. Why am I such a strange creature?... every time, I have time, I don't use it, I try to use it, it won't work... and it all boils down to the umpteenth minute. It's terribly exhausting, and I try my best every time to avoid such happy endings, but alas... Anyway, the good thing is I now have one thing less to worry about. But it's mumbling season again. Mumbling season is the time of the year when I suddenly lose my linguistic prowess in one or more languages I use. For instance, right now I'm feeling uncomfortable speaking English (writing is never affected). The words kinda roll up inside my mouth and I also can't find the right words. I've also suddenly lost my accent. It's so utterly frustrating. It's worse when the same kind of thing happens with Bangla. I then have to do with English, or stuttering Bangla. But we Bangladeshis are very emotional about our language, and people who're convinced I'm trying to be a snob with an Anglocized Bangla accent or simply arrogant don't give me nice looks at the end of our conversations. By the way, Bangla, or Bengali, is my native tongue, but English was the language I learned first. Therefore I pretty much use both of them in my head. Imagine my distress when I'm malfunctioning in either of these... or in both. In such cases, I generally end up being mum or uninterested in conversations for some time, trying to get my mind off it knowing that it's going to go away in a couple of weeks. I don't know why this happens to me, and I'm not pulling your leg here. This really happens to me. I've given the thing a lot of thought over the years; almost nobody believes me, so I've given up talking about it. Is this a psychological thing? I don't think so. Everything else is okay. I'm perfect or as good as I was yesterday in every other respect. It's just the language part. Perhaps a neurological or genetic disorder? Is there any literature on this? Does this happen to anyone else? Nowadays, I'm learning Sanskrit. I'm thoroughly enjoying it, but God knows what's going to happen when Sanskrit is the only language I'm fluent in, in some foreseeable mumbling season. I told you I was weird. Posts will be more frequent, and hopefully deal with more realistic issues.