Hi, OP.
Firstly, just to say it's always a risk posting on public forums about infertility issues (through bitter experience!)- lots of people who haven't been through it themselves just do not understand - for example the suggestions about fostering/ adoption.
Please pay them no heed - there are always people who will not understand and you can't make them. Take a deep breath and focus on yourself.
I've been through similar to you with male factor infertility and needing to use a donor. It's a hard journey and I wouldn't wish it on anyone. I can completely understand why you might feel you are about to have a breakdown.
I'm so sad to hear you are facing a potentially childless future if you stay with your DH. That's not what you envisioned for yourself, but it sounds like he is OK with it and doesn't want to use a donor.
So you are faced with a stark choice, really - stay with DH and not have a child, or leave him and go it alone. A third option is to try and explore it with him/ try to persuade him - how certain do you think he is and how much do you think he's thought about it? My DH really struggled at first, but he has come around, it is possible.
I do recommend you find a counsellor who specialises in infertility. They usually list on their website if they have areas of interest, and a lot of counsellors will offer a reduced rate first session so that you can 'try it out' and see if they're a good fit. I know it seems like a lot of effort but the truth is it's worth it, and you will probably find you only need to try one or two who specialise in fertility before finding someone who will understand.
I wish you the best of luck whatever the future holds, also happy to chat via DM if you want to.