Hi Anjelah,
Sorry to hear you're having such a rough time. I, and I'm sure a lot of people here, can certainly relate to the experiences and feelings you've described.
In terms of your question about truly knowing if a med works, I think it can be difficult to assess, especially when the effects are subtle. It's a very subjective question that ultimately would be best answered by you and your doctor or therapist.
I was on a medication last year that didn't seem to be helping (and carried some annoying side effects) so decided to drop it. I was also in a relationship at the time and my ex was very anti-med, so I'm sure her influence factored into my decision-making. Interestingly enough, when I told a close friend about stopping the med she was against the idea and thought I was doing much better on it. Upon reflection, I really was doing better, just not feeling as good as I would have liked to since my expectation of medications was much higher than it is today.
Subtle effects can be as simple as finding it a little easier to get out of bed or being a little less resistant to the idea of doing something socially. It may even take some tracking of your mood and activities to make the determination.
Sorry for the long-winded post. Just wanted to mention one other thing re: suicidal ideations. It doesn't sound like it's a serious issue for you, but it's something that's worthy of mention to your doctor or therapist, if you haven't done so already.
Take care,
Flint