I Have Mild Meibomian Gland Deficiency

I seem to have mild meibomian gland deficiency and need tear drops ever 2-3 hrs. I currently use optive eye drops, take omega-3 supplements and a multivitamin. I also do warm compresses/lid cleaning.I am a 28 year old female. 1.Are there preservative free drops available in India? I have heard of Celluvisc, but those are supposed to be thicker. Are there other preservative free drops? 3. I have also heard that mucolytic agents like N-Acetyl-L cystine can help reduce symptoms.I have read that mucolytic agents can cause ulcers/asthma and other side effects.Are they safe?I have nasal allegry and wake up with a running nose everyday, hence dont want to trigger asthma or any such thing.Can you prescribe me a low dose? 4.My schirmmers test,complete blood count ,blood and urine fasting and post-prandial sugar are normal.My TSH results are normal too. SS-A/SS-B auto immune factor,are also negative. Could inflammation be the reason? Are neuro transmitters/hormones the culprits? Is there other any test I should undergo to narrow down? 5.Can you let me know of any food supplement with anti inflammtory properties? 6.I was asked to try out doxyxycline .Is long term (say 2-3 months) of anti biotic course not harmful to the body and cause ulcers/make bacteria resistant to these or cause other side effects? 7.COuld depression have triggered it ? If so can I hope it will go away?