Do you have clothes pins or a nose plug that you can wear whenever you attempt to change diapers? One of my friends couldn't change a diaper without some sort of nose plug, because every time he tried he would vomit and then there would be an even bigger mess to clean up.

I am assuming with your sensory issues you can't breastfeed and are using formula? Do you have a rocking chair (more for you, but it might help your baby stop crying as well) or some kind of automatic rocking device for the baby?

My husband and I are planning on adopting/foster care of an older child. There is no way I could have cared for a baby. I have problems lifting a few lbs, a baby even for 1 hour would exhaust me for days. (I have another condition in addition to SPD that drains my energy and strength quickly).

You personally may benefit from some meditation techniques. That way you can shut down your senses temporarily while you need to do a critical task like feed or clean your baby. I use meditation techniques to help me get out of panic attacks. My panic attacks are triggered by crowds where people are touching me randomly and lightly all over my body as they pass by.