You could just wait a year and re-evaluate? But, you don't say your age, and therefore, we don't know how much time you have to play with.
I have 2 kids, that are only 19 months apart in age. Boy (19) and Girl (almost 18). I am sure that my life would have been harder with one, because they played together when growing up, and holidays were definitely easier, as they had each other as companions.
Now that they are adults, they are much closer than I could have imagined. My son has left home (for Uni) and my daughter regularly travels and meets him for lunch. They are supportive of one another, in many ways.
I am very glad, that when I am no longer here, that they will have one another, because in my experience, blood is thicker than water.
I have had friends come and go in my life. I've been shat on by so called friends. My BF even slept with my then Husband! I've been cheated on by a husband (now an Ex). How many times has my sister shat on me? NEVER. There are 3 women, who I could trust with my life: my Mum, my Sister and my Daughter. And only one of them is on my generational level.
But, you can't force yourself to have a baby, if you really don't want one. But I am very happy that my children have a sibling, and very grateful for my sister.
My BIL is an only child and he HATES it. So much so that he says he will never inflict that one their DD, who was conceived by IVF, and therefore they are in the process of adopting.
But obviously there will be many that are ok with it.