Thank you for introducing me to a new (to me) band! Yeah, life can be kind of a roller coaster, and everyone's interests ebb and flow (as you've discovered with yourself and your bandmates). Sadly we only have so much energy to roll with it, and I'm sorry you're at a low energy area right now. Those suck, and it is VERY difficult to battle inertia and muscle back into the fray.

Art is kinda cruel in the way that it makes you choose - familiar and possibly uninspiring, or new and possibly a frustrating dead end. The reason I mentioned the M8 was largely due to its pocketability. It's not much bigger than a large smartphone but it's a whole production device with instant-on and a sensible design. Work on stuff during lunch, at the park, on the bus, etc. But there is a learning curve, so spending a lot of energy you might not have may get frustrating if it doesn't click right away.

One thing you might try is suggesting gentle deadlines or challenges for yourself and your bandmates - like write a catchy 10-second jingle by the end of the week. Or parody the chorus of an existing song by the end of your next phone call. A deadline for something silly is easier to meet, and you all would have created something and had a little fun.

There are a lot of amazing people here suggesting different things you can do, and I notice a lot of their ideas are creative activities. I think you can land on any of those and find satisfaction. There's no high like creation. No matter what, remember that things always change. If you're at a low point, it can't last forever, especially if you keep powering through it. You'll come out ahead.