I could have written your post when my twins were this age OP. There was many a time my DH got home and all three of us were crying at him. I honestly felt like they were miserable and they hated me. It will pass I promise you.
In the mean time coping strategies:
Plan something every day. Even if it is just Asda, a walk or going to the weigh in clinic.
Walk a lot. A crying baby is far more bareable outdoors than in.
Try to join some baby groups. Do you have any church ones near you? I found there were always grandmas volunteering to make drinks who jumped at the chance to have a cuddle.
If there is a twin club near by then go, everyone gets it. Makes you feel so much better
I have a few twin mum friends round the country so pm me if you'd like to tell me where you are, I might be able to introduce you to someone.
Also there's a Facebook group called twin mums in the uk. I'm certain you'd find someone near by on there. And it's great for advice too.
Musical instruments (or anything noisy)
A fan (when it warms up) with ribbons attached for them to watch
And nothing wrong with a bit of baby sensory video on YouTube.
I know the feeling of guilt re not taking them to classes. Do you have anyone who could commit to a class a week with you?
You've got this, don't doubt yourself, being a twin mum is hard!