Congratulations on your pregnancy OP. I'm sorry the father is being so unpleasant.
This is such a personal decision that only you can make. It sounds like this is very much a wanted DC by you, which is wonderful. I don't think the perspective of the father is something you should factor in, save that you should recognise it's likely that he will continue to be unpleasant for the duration of your pregnancy and as your DC grows, and that might be painful for you both in the long term. In terms of the pregnancy itself, it's your body and ultimately it's up to you what happens next.
If you decide to go ahead with the pregnancy, it would be a good idea to turn your attention to ensuring you can provide a loving, stable and secure home for your DC to be. Parenting is hard work, and I found it hardest of all in the early days. You will need a support network around you, be they friends, family, paid help or a combination of those. You don't need input from a father who sounds unkind, untrustworthy and unpleasant.
I would suggest trying to surround your DC with positive male role models in the absence of a good father figure, and I would echo the solid advice of those above about birth certificates and maintenance.
In case it's of interest, my mum is a single mum. My childhood was fine, but if I'm brutally honest I did feel the absence of a loving father (I still do, to be honest). I saw how much easier life was for my friends who had fathers who were on the scene and financially supportive. But that's just life, and it's rarely perfect. I'd much rather be here than not, and I'm sure that those friends who have loving and supportive fathers will have their own gripes about the parenting they were provided with.
These days, blended families are ten a penny, so if you do decide to proceed, it doesn't mean that you won't end up in a loving relationship with other DCs down the line. Blended families come with their own perks and challenges (as evidenced by the threads on here), but you won't be short of support from those in similar situations.
Wishing you all the best, whatever you decide.