IDK….
Since your key won’t come out is the column shifted into “Park”?
If the column isn’t in park the neutral switch will prevent starting and the key cylinder will keep the key from being removed.
Did you bump the neutral safety switch while working on the switch? The neutral switch I am using does not lock in position and can easily be knocked out of adjustment.
Do you have a tilt column? If so is it super wobbly?
Have you worked on anything else recently?
If that stuff is all good:
Test the power wires that feed the cab, should be 2 of them IIRC. One is from the battery positive lug at the starter, there’s a fusible link right where it hooks to starter. The second wire comes from the alternator and goes to the bus bar near the brake booster, there are fusible links at that bus bar too.
Maybe give the starter some light hammer taps and try the switch with a screwdriver again.
Have someone work the switch while you test the purple wire on the starter solenoid with a test light. Should light up when they hit the “start” position.
You can test the wire at the NSS also, IIRC there should be a 2 wire connector with a yellow wire in and purple wire out (purple wire goes to starter). Test purple wire when switch is in “start” position test light should light up. If no light test the yellow wire should light at “start”. If the NSS is getting power in but not out it is either not in park or neutral, not adjusted correctly, or worn out.
Check your battery voltage, should be at least 12 volts
Check the grounds, battery should ground to either the alternator bracket or the front of the block somewhere
While checking grounds check the integrity of the battery cables. Should be clean and tight at the battery. Cables can be corroded and rotten inside the plastic shielding so if you have tons of corrosion it’s a good idea to check