I would like to explore a polyamorous relationship, however my biggest problem, besides my current partner being monogamous, is that I have depression. I'm not sure that I can be as emotionally available as might be needed in such a relationship as I already have trouble being more than just a husk half the time. I know this is more of a depression problem but if you have any advice I'd like to hear it, thanks.
It sounds like you know that a major issue is your depression - so you sort of have your work cut out for you, in the sense that the solution is treating your depression. If you’re not already seeing a therapist, start! If you are, start talking to them about this issue. Let the know that you feel like “just a husk,” and that you’re worried this is impacting your ability to be in healthy, fulfilling relationships. Ask about other treatments and therapies you can try. Depression can be tough to treat, but it is treatable, with some people finding relief from everything from lifestyle changes to CBT/DBT to TMS or ECT, and everything in between. Check my mental health resources for a starter!
In the meantime, you can continue polyamory-related self work, like reading about polyamory, working on identifying your own relationship needs and goals and desires, and building on your communication with your current partner.