Severe dry eye. Genteal eye gel as well?

I have severe eye dryness ( in strip tests for eyes for 2 and 5 - Left and right eyes respectively) Am using lubimoist eye drop ( 4 times a day 1 drop every time ) & genteal gel at night time . 1. Since these have preservative I wanted to know is there a safe non preservative options for long term use ? Or can I use non preservative ones along woth this if I need to lubricate more than 4 times ? 2. using above medications for 1.5 month now how long can I apply Genteal eye gel as well ? I have had eye checkup done every 6 month and all other thing is good .Just have left eye twitching occasionally for few months which they said could be stress dry eyes etc . Please help me for these 2 queries . Thanks!