Hmm OP I have to agree with @Screwballs a bit here. I’m really sorry that you’re struggling but perhaps the fact that your previous partner left during your pregnancy has increased your anxiety and you are projecting this on to your current partner.
Doing a hobby once a week is completely fine and he shouldn’t have to quit this because you are pregnant. It’s important that you have your own hobbies too and get a similar amount of time off to do your own thing as well though!
I can see the perspective of his friends and him, you’re not happy with him doing the hobby and have now claimed you’ll commit suicide if he goes to band practice - this does seem like it could be controlling, or at least coming from a place of needing healing, or having a very anxious attachment style, or feeling that the only way to feel loved and connected is through drama.
Perhaps you were genuinely in need that night but perhaps you were unfairly creating a dramatic reason for him to stay back rather than addressing the root causes of your anxiety.
Only you know what really happened and what’s really going on with you. You could either be a very balanced person who was having a genuine crisis or you could be someone who needs to do a lot of work on your emotional maturity and look at your childhood and how you saw relationships modelled in the home.
But, if your partner is in other ways a great guy and helps you out and is loving and understanding, I think I would give them the benefit of the doubt around their perception of your crisis. Also, someone who works hard and is in a band and cycles sounds like someone who is interesting, organised and has their act together rather than a cocklodger!
I will however say that it’s not on that he discussed this with his friends and told you what they think, on the face of it that was unkind. But, we also don’t know what kind of stress he is under so maybe he was at breaking point too so opened up to them to get an outside view.
Perhaps some counselling for you to address any trauma you have from your previous break up to ensure you’re not letting that effect you now, would be useful for you. Perhaps that would help you communicate what you actually need from him. I don’t think it’s that he doesn’t do his hobby, but maybe you’re needing more reassurance of the stability of your relationship in other ways and therapy could help you pinpoint this to ask for what you need before the relationship is too damaged.
OR he could be horrible! But it’s impossible to tell from your description of the situation.