I feel deep down I would regret this abortion.
Hi again op. I think it is clear that, emotionally speaking, you want to keep this baby. It must be awful being happy about being pregnant and not being able to show it.
In practical terms though, babies need more than "just" love. And of course, your dp needs to take responsibility for his part in the pregnancy. It is not mature of him to shut you out at a time when you need him most. How strong is your relationship generally? Is he upset because of finances? He is allowed to be shocked initially but he needs to be practical too.
Are the other people around you disappointed because of the timing of this pregnancy? In other words, are they stretched financially; were they hoping that you would go back to work now your dd is in nursery? How much financial support does your dp give you? And your parents?
Depending on all the answers above (which you don't need to post here) and as your mother is supportive, why don't you and she do what pps have suggested and seek advice from any organisation that you think may be able to help and form a proper idea of the benefits you would be entitled to, and basically an idea of what financial provision and practical arrangements you would need to make to support your second child if your dp does not. And obviously you and he need to talk about finances too.
To a certain extent, harsh though this sounds, if you don't want lots of people involved in the decision making (and again, the ultimate decision is yours) you (and your dp??) need perhaps to think about living independently of everyone else. You need to put together a financial plan about what would happen if you decide to go it alone if your dp is not supportive.
I am sorry your mil appears to be racist. You need to leave her firmly out of the decision. She can make decisions about how she will respond to you and the baby (should you decide to have it) once you have made your own decision about things. Just park her to one side for the moment but take in to account that she may not be prepared to take on two dc overnight at weekends and what you would do in those circumstances.
Good luck op
Again, this is very much your decision, but maybe the people around you will before supportive if you show them you have done the financial hwk and planning. And if you decide to go ahead with the pregnancy, how about looking in to studying while your dd is in nursery so that you can retrain?