This does seem to be all about you OP and not about the needs of another human being that will do far better if they had a parent around for longer who was younger than the timescales you can offer.
I personally think you need counselling.
You are using a baby to meet some unmet need inside of you.
The thing with a baby is you can’t change your mind. It’s with you then through your old age. As a very young person. I think that’s cruel.
Of course you can’t fill this gap with material things. A Louis Vuitton handbag or a trip to the Seyshelles can’t compete with the huge emotional rollercoaster of love but so many many other emotions, that a baby can offer.
I’d be more inclined to try fostering. You will get the same intensity of love and all the dynamics of a child parent bond but you can step away from that child if you need to.
It’s a huge commitment going into baby years aged nearly 50.
I can hardly take care of myself at this age, let alone the thought of tantrum twos, the awful threes.
Dont forget also the risk of having a child with disabilities. You’re working against nature. Nature may not be on your side for that reason.
You need to fill your life with meaning and deep connections. This is what you crave. To see growth of something, anything. You think a new baby can offer you this but I can’t help but wonder if this is fair to the child.