Absolutely. I was an absolute loner for the better part of a decade. Then my depression just disappeared. I joined a community around a streamer and had loads of fun. Just find the intersection between your preferred subject (literary analysis, anime tiddies, etc.) and your preferred communication method. (Text forum, voice chat, real life meetings, etc.) You’ll find at least someone you can hang with, maybe more. Just go at it with openness and joy.
Stress is the obvious answer. You won’t be able to guess what is causing it, so don’t start speculating. You can try to impress upon her that you are a safe outlet for that stress if you are able and willing to really be that for her, (Don’t just jump at it because you are curious. You might not like what comes from it, and it’s worse to pull back after the fact than to not offer at all.) or you can just be a source of stability while she works through it herself. Use your best judgement.
This is absolutely the answer. If it isn’t funneling money away from actual value creation and into their pockets, it’s evil in the mind of the investors.