How to when you are stoped at a light or etc it shakes real bad put not in nutral

take it to your local auto parts store they will check the error messages from the computer for free and might be able to help you find the part you need... If not bring it to a repair shop.. Could have a bad spark plug or bad injector etc to many things to list.

Blinking means that the problem is so bad that it can damage the engine if you drive it. You need to get a code reader from an autoparts store and read the codes to see what the issue is.

Could be a long list of things.
Ignition, fuel, exhaust, vac leaks, etc.
Is the check engine light on ?
Have you checked fuel pressure ?

could be a clogged up fuel filter, its not letting enough fuel through to engine. good-day !

depending on year???? may of bent cable fixed end at trans or under dash at column??

on the right side where the timing belt cover is there is a fat wire harness...over time from the motor rocking back and forth on the motor mounts will wear even short or break these wire diesect the harness and inspect......a simple diag test is to put it in nutral and manualy rock the the motor back and forth front to rear with a long bar to see if acts up doing this if not ...it may be a internal transmission tourque converter locking up issue...

did the same to mine I have an 86 same model as yours it sat for 5 years it would idle fine and run for hours in nutral then i put in gear and it would shake and eventualy turn off! took me two weeks to find the problem on mines it was a bad ctalitic converter and a bad distributor rotor it was not suppling enough spark to the plugs! now it runns like a champ talk about a real truck its a monster nothing close to it! all new trucks are junk they fall apart!

try it in nutral put in park and hold up and or jigle up and down in park, dont come out of park jiggle while u hold to start,check large fuses anything marked starter check cables cable ground to engine ,check nutral safty switch check starter , and starter wire ing wire at starter with test light small wire on starter while someone trys to start jeep ground test light to a good ground and hold point on small wire on starter it should light up if it does your starter is bad ,if it doesnt light up check ignition switch on steering colum ,most likely bad

when was the last tune up done and fuel filter was changed?
there is no spark plug wires I had to replace the boot for the number one cylinder on a 2000 expedition that was also having the same problem if the check engine light is on take it to auto zone and they will put it on a tester free of charge and I hope and pray that it is not the problem like the one I am working on right now I am replacing the upper and lower intake gaskets

More than likely it is your engine mounts. If you have cracked or deteriorated mounts, the engine will vibrate with the symptoms you have posted.