The way I accomplished this achievement was I followed a few simple rules
1. Max First Aid on Renegade Tree then only Upgrade your Combat Tree
-Most enemies don't give you enough time to use your tech abilities
-Being able to roll away is key to running away and surviving fights
-Stealth is not an option in many areas
-Combat Trance is also really helpful
-This also gets you the Specialist Achievement
2. Be a Bad Guy and take serum from everyone
-This will ensure you have enough to buy supplies
-This also makes it so you can simply intimidate people instead of fight them and still get the quest done
3. Always be stocked with Health and Bombs
-Health can be made but is 5 serum cheaper when purchased from a vendor
-Bombs are great for knocking down any enemy to give you time to heal or quickly attack one enemy
-Warning bombs do hurt your companions
With these in mind here are some other helpful tips for your play through.
Always have your friends with you, the game will give you options to go it alone, DONT. Even if your buddy is useless just put him into defense mode. This benefits you because some of the enemies are focused on him and not you.
If you have the option to spare someone - which will end the fight early - do it! Unless you really want to kill that person this allows you to progress faster and save your gear for other fights.
While your scavenging sell your useless junk Example: no point in having 100+ pieces of cloth or scrap if your not using it.
My preferred weapon was one that had the capability to wound, this helps you either kill your target faster or allows you to bounce around from one target to the next.
Final tip keep trying! This game can be super cheap at times and can really test your patience at certain points and you'll need to approach the same fight but a different way. Example: entering from the side and instead of the front or first targeting a certain enemy. Good Luck!
Tried to keep this as spoiler free as possible, I definitely welcome your feed back on whether this was helpful to you.