Does the medication really help?

Hello looking for general support really. I've been with my husband for 11 years. Five of those married. It's the same as everyone else really, we were great until we got married and then he totally changed. We got pregnant quite quickly and he was overwhelmed with the prospect of becoming a dad and I couldn't do or say anything right. Covid hit us hard financially and the loss of work sent him into a depression. I noticed huge mood changes during this time and every 3 months he would say he wasn't sure he wanted to be with me or want our life together. Then he was would come back around and things would be good for a while and the same would happen again. His moods switch so rapidly sometimes it's hard to know what  I said. Issues with my slowness to respond or also me responding too directly in the wrong tone have caused so many issues. Around  a year and a half ago after a breach of trust, he went into the therapy that first suggested ADHD. We then did another year without a formal diagnosis. This year he threatened divorce 3 times during a fight which he started, but apparently I was to blame for. I'm happy to accept I am not perfect but I do struggle with the temper escalation and I am always accused of being aserbic or acidic. I often feel like he has two personalities, one for everyone else and then the split one with me. He works relentlessly which is where his hyperfocus goes. Then when he gets back he either crashes from exhaustion or illness. He won't stick to any exercise routine as works too much and has quite a transient job so he can't find a routine for diet and exercise together. He finally got a formal diagnosis of ADHD combined inattentive and hyperactive at high levels and then he chose not to take the medication (Ritalin). I decided to at that point to end the relationship which was extremely difficult as ii of course love him very much. After a few weeks he wanted to try the medication, and we have started to mend. However he has been hit with an illness that has delayed starting the medication by another two months. And I can feel the anxiety building up in me that I'm relying too much on this to change things. Has anyone else had experience with great improvements in their partner after the medication? Am I pinning too much hope on this?