Someone with experience...

I have had eye plugs for years now and they do help, go for it the first set that get put in hurts a little but then it gets better and you'll feel the moisture immediately and your eyes will feel so much better...
Opt for only the lower lid eye plugs, I've had both upper and lower lid plugs and if your eye's are not extremely dry then you won't need the upper lid plug placed...it's done in office take less than a few minutes to have them place, but insurance might not cover them. for me it went straight towards the deductible and they run for costs about $400.00...but yes, they help without them my eye hurt so very bad and get infected.
When your eyes are dry and hurting chances are very good you can get an infection in them and you need to avoid eye infections as they can damage your eye's.
But yes, the plugs help. Sounds like a good eye doctor...

Once you get them placed in your eye's will feel so much better, dry eyes can lead to infections and then more eye drops, and if your that dry it's worth it. You should be able to call the eye doctor's office and have them check to see if the eye plugs are covered. Tell them you need to know the costs before getting it done. After so many years without tears I finally know what it's like to have tears and it's so much better...try the warm compressess for now...warm water compressess will help some.
I was dx in 2009 and I literally had no tears to wet the paper strip for the dry eye testing, he couldn't get 1 tear on me, not one...and I had eye sand caking and a eye infection and I was hurting bad.

Yes, the plugs help your eyes with tears and moisture, they will help...it's like night and day without them, I know exactly when I need new plugs because I can feel the dryness...well since my eye doctor couldn't get or see any tears he only tried the test strip on one eye and I remember him holding it there for a minute and no tears so he gave up, I'm not sure if it got stuck as this was years ago...Typically the plugs wi;; last for 1 to 1 1/2 years, for me the first year I need them replaced at the 6 months mark, and then again at six months and now I get between 9 months to a year, but my eye dryness is really bad...I have a complicated eye history...3 surgeries on one eye, early onset macular degeneration, eye allergies, ect...

fish oils omega's 3's can also help for the eyes and parsley, eat parsley it's a good eye vitamin...

I have sjogrens, that's the big cause of the dryness the other conditions Just make the dryness worse, yes.
If your not low on a D vitamin then do not supplement D.
I use a strictly eye vitamin called "Right for the macula" its more cod fish oil, but parsley will help the eyes it a good food to try for good eye health. A good plain omega 3 is good mine was prescribed omega 3...called Lovaza brand name...my vitamin d is also prescribed but I'm low on it and its only vitamin D ...ask your eye doctor what you should take and your pcp (primary) doc can check if your low on the other vitamins ..bloodwork...but d should never be supplemented unless your low as too much d can be bad...

Sounds like you need another doctor, a blood tests is the first test, for Sjogrens and from there a lip biopsy. Try finding a Rheumatology doctor that can specializes in Sjogren's. My RA Doctor was recommended to me by my eye doctor.