LDR – Partner (F/25) Seems Stressed or Off- What to do?

Hey there, long time lurker in need of advice!

TL;DR: LDR GF (F/25) seems to be down, stressed..and hasn't been feeling well..but I can't be there to help her out during this time…any advice? We talk about the future and have a very communicative relationship.

I (M/29) am in an LDR and my gf (F/25) seems to be really stressed recently. Currently we can't meetup due to travel restrictions. She seems to be overwhelmed of sorts. Most recently she hasn't been feeling well..maybe lonely. I feel like she's just been a bit less enthusiastic about the small things. She asks what I've been up to..and will tell her fun adventures, hanging with friends (social distancing, course!) or just hanging out, but she doesn't seem too inquisitive. Kind of just.."oh that sounds cool.." But doesn't go into 'depth'. I feel like there isn't the same 'lust for life' that I have..you know? I ask what she has been up to and recently she kinda just says..watching tv, youtube, cooking, on the phone, etc. She hangs out with her friends too. Bike rides, meet in the park, etc. She seems to have a fair amount of people to hang out with guys and girls.

We'll still talk for hours but she just seems a bit down. I'm not sure about her mental health history.

We have a passionate relationship. We've met many, many times. And there is a lot of love. We plan out the future.

It sucks to hear her like this..especially when I can't be there to help, like get groceries, cook, support, etc.

Any idea as to what this can be? Or how I can help from afar? We're not on the other side of the world but we can't meet up either…at least yet.

Thanks!!