I’m sorry

. You get to decide what this chapter of your life looks like. Depression is real, but You’ve supported him and his depression for 2.5years and should not feel guilty if you do not want to live like this for the next X amount of years.
You are empowered to make your own life decisions, and to ask for what you want / need. If his current medication plan is not working, he needs to seek other options that may work better.
I’m not the kind of person that can easily take care of grown, capable adults. I get resentful, which is not good for me or the other person ... and the whining / whimpering would be an absolute non negotiable. That would be the final straw. What grown man just runs around whimpering so that you’ll know how unhappy he is? :/ I don’t even allow that type of behavior from my 10 y/o.
There is no right or wrong answer. You have to decide what you are willing to put up with (which could be s lot or s little), and what you want this chapter of your life to look like.
Lastly before you go jumping in to another relationship, pls take the time to heal and focus on getting in to a better mental state.