Body Skin Creation HELP

[EllieLux]

I'm desperate for some help and/or advice revolving around body skin creation for mesh bodies. I have my upper texture relatively done, but the seams for the torso > arms are killing me. I'm not sure how to paste my skin onto a 3D mesh in blender, or even how to import the ruth mesh files into substance painter. I understand that creation is very gatekeeped but im desperate for help here. If theres a way I can paint my skin like I currently am in photoshop, and then inputing it into blender or substance painter to melt the seams together it would save my life. If anybody can provide me with links to videos and/or infortmative sites I would greatly appreciate it.