Your Starter
Of all things, try this, Get a hammer and give your starter a couple of slight love taps and see what happens. If it starts then you either need to put new brushes in starter or it might just need a bit of cleaning on the inside. Easy to do,
Also you should have a fuse under the hood for the ignition. look in the power dist block. And if you have an anti theft on it, remove the negative battery cable and let it sit for 5 minutes, reconnect, if it starts after that, then it is related to your anti-theft. As for the truck dies when you put in gear, that would make me think either Alternator not producing juice like its sposed to, might need new brushes. After you get truck started again, remove a cable from battery as its running, if it dies you need new brushes in Alternator. Or your having fuel issues. maybe a plugged filter.
If your starter isnt doing anything and if your truck is a manual try bumping the truck in gear, your starter may be in a bind or just cannot pull the gear back to where its sposed to be. if yours is auto then grab the belts and stuff under hood and try and rotate engine just a scratch, if you do and then if you hear a click then your starter was stuck. I would suggest just pulling starter and new brushes and a good cleaning. that should start after that.