You know, if this relationship had any future, no matter how difficult he found you to deal with, he would be educating himself and trying to find out how he could best support you. Instead, he is actively shutting you off, arguing against you doing anything which could help with your illness (eg taking medication) and making grand protest gestures of his own by undermining your parenting of your DS (who I assume he hasn't even known for a year) and driving off with him when you disagree with him.
None if this is helpful and he is not giving off any signs that his relationship is good for you, in the long run.
Even if he was a reasonable man (which he does not appear to be by any stretch of the imagination) listening to someone going through a severe depressive episode is a hard one, especially when your partner seems to do more to talk themselves down deeper into the pit. Ex used to get home from work (when he could go into work, instead of staying in bed all day) and could ramble on for hours, expressing some extremely dysfunctional and paranoid thought patterns.
I'm not a therapist, but what I could do was
-offer practical suggestions where he was making a simple problem overly complicated
-reassure him that it as doubtful that his entire workplace was plotting against him
-try to encourage him to seek further help because his current treatment was obviously not keeping him stable and functioning
unfortunately, I also had to
-explain to him for what felt like the 100th time (for example) that I know that his younger brother got a bigger bedroom than him and that it's not helpful for him to dwell on supposed firstborn nonsense based on events 2 decades ago and that he really need to forgive and live for now
-explain that, no, I can't fix all his problems for him if only I xyz. he needs proper professional help (unlike you, he never did seek this beyond the ADs he'd been taking at the same dose for years)
-refuse to take his side when he berated and pleaded with his mother about completely trivial perceived sleights from his childhood. And deal with the fall out from that, how disappointing I was, etc.
I'm not going to suggest that you're the same as my ex, but this was a lot to deal with and we'd been together for some time. There was other stuff going on that had soured the relationship a long time previously, but I was still able to nod and offer perspective without completely dismissing his need to talk.
Your boyfriend, in a relationship so young that you should still be wanting to giggle like teenagers and jump each other's bones at all times of day, doesn't even want to listen to you. You really do need out, because living with this is going to make recovery even harder than it should be.