Frustration at partner needing constant support

I'm the default parent in my household and have a lovely 3.5 year old boy. Like many households, we are both working full time jobs to make ends meet. My partner has mental health issues, and constantly falls into a "spiral" when certain challenges occur in his life. Most recently, it was a meeting that ended poorly at work where he was so upset he walked out. Now, I tend to think of myself as a caring individual and I did my best to be supportive the day this incident occured. I asked if I could get him takeout food, or do anything to support him. He went to lay down, and I took over cooking dinner, bath time and most of bedtime routine for my son. I am completely able to handle this and was not upset in the slightest.

After my son went to bed, I went into our room and found him in the pitch dark with his eyes closed. I sat on the edge of the bed and asked if he just wanted to go to bed, or if there was anything he needed? He quickly snapped that it would just be nice if I could show him love "for once" and he shouldn't need to ask. I asked a follow-up question and he jumped out of bed and went downstairs for the rest of the evening.

I feel as if he expects me to take care of him in ways I cannot provide, and refuses to acknowledge that I am an overworked and tired parent. I simply get spiteful anytime he takes this attitude of my needing to "help and take care of him". I empathize with mental health struggles, I have them too. I do not rely on my partner to take care of 100% of my emotional needs. I also feel spiteful because if I'm having a bad day I'm still a parent. I still have to get up and do shit and supervise my child. I don't lay in a dark room and rot away waiting on someone to come "help" me. I've encouraged counseling, different meds etc and nothing changes. I personally engage in counseling and find it powerful and life changing. Am I wrong for expecting him to handle some things alone? Am I wrong for expecting him to articulate his needs?

Rant over.