It sounds like you're in a really bad place. I'm very sorry you're feeling this way. Being that you've been thinking about OD'ing on your meds, it doesn't sound like you're safe, especially along with the swings you're describing. Please don't harm. I know how difficult it can be to quiet those thoughts and not act on them. And also how quickly the thoughts can turn into actions.
I'm not preaching, the things you're feeling right now are exactly the things you should discuss with your pdoc.
Do you have a therapist, friend, crisis line you could use right now? If not, I hope your group session provides some help.
Many of us have been in the same or similar place. Please stay safe.