Increasing Irritation

All the information which has been given already.... plus.......

Water water water. I made a point of refusing to go over a patch more than once without re-lathering or at least re-wetting and spreading some lather over it.

Any time you shave any part of your face that doesn't have some form of moisture on it, you will get red bumps.
 

Yep, you need to grow a beard fella.

Could you PM me what razors and blades you now want to get rid of, i'l offer best value.
 
I always do a two pass shave shave daily - WTG then XTG on the face and 2 x WTG on the neck. Growth direction on my neck is all over the place and I have one particularly tricky patch.

I don't always get a really smooth shave on the neck however, but it's better than an unsightly rash and the irritation that would go with it.

I use Techs and a WS Classic, all of which are known to be mild razors. I also have a fat handled Tech with the slotted head and that is a more aggressive shaver and never gives as comfortable a shave on the neck as the others, regardless of blade used.

My solution therefore would be to used your mildest razor with your most agreeable blade and only go WTG on the neck.

Have you tried Sudocrem on your neck? It's very white on application but applied the night before it will have soaked in by morning.