Op, I was 45 when DS was born (I know, it was a real shock to discover I was pregnant.)
We agreed I should continue with the pregnancy so ex was in agreement. The issue was he turned controlling and abusive as soon as DS was born. It started while we were still in the maternity unit. He didn't get up once, never changed a nappy or give a feed. He was never involved positively in any way. We left when DS was two.
From the day we left, things got easier. I could organise my day, engage a childminder, go back to work, make plans for the future without ex messing me around. Being able to take decisions quickly and not have to compromise or negotiate is one of the benefits of being a single mum. You can focus on your child and not have a big man-baby deliberately messing things up to manipulate or get attention.
It is hard work, but I 'shrank my life down' to what I could cope with at the time, got me and DS in to a stable routine and then rebuilt life from there.
It took about 12 months for everything to fall into place and we've generally been happy and settled since. DS is now 16 and a joy.
Think hard about what you really want, but don't be scared. If you have a good job and you are generally healthy and capable, you would have no issue raising a child on your own. Especially if you have family support.