Based on your answer, I should restate what I meant by right gear. Right Mods on the right character, sorry for that confusion.
To begin with, you have (in my opinion) a bad team setup because it's missing key characters that makes it work. If I can infer from your original post, you are missing 1 key character that makes a droid team works, specifically HK. Assuming a few things here, since you listed Poggle first, I assume he is team lead. I would use Lumi as team lead for that dodge over damage, it served me well for the first 3 months when I started playing the game.
For GW, node 6 onwards is geared towards lvl 80 g9-10 team, so finishing node 12 is always going to be hard if you don't have a lvl 80 g9-10 team and you will not always finish especially if you only have 1 viable team. That's the whole point of progression, to slowly gain power to finish consistently
It took me 6 months to get a G10 7s Rey, G11 7s Lando, G10 ST Han and now I'm finishing GW 100% all the time including having easy mode node 12 (also helps that now i also have a backup GW team that was the original team I used). My original GW team was composed of HK lead, 88, 86, RG and Biggs, and with this team I still had about a 90% GW completion rate but had to swap characters out to heal or sometimes to sacrifice but mainly on the hard nodes like 9, 11 and 12. I was also at 50-50 completion of node 12 during my first 3 months but after that, i've had a very high success rate.
If you use a g8 team to do node 1-6, it is a waste because if you pay attention you would have noticed that node 1-6 are usually teams up to lvl 70 and once in a while node 6 would be lvl 80 team. This means you can save your primary team for node 7-12 and they will still have their full armour and health as well as cool downs while using your non-level 80 characters to do node 1-6
I'm not sure whether you are in a guild or not, but being in a well organised guild, helps in progression a lot. i.e. my guild can finish a T7 in 3 hours but we have a 12 hour freeze once we hit p3 to let all our guildies get logged into the raid rewards, this way even our very casual guildies are getting T7 raid rewards to gear their characters up.
My last advise as F2P, is to focus farm, don't farm multiple things all at once. Get a scoundrel team that can finish tier 3 credit heist, I would focus on that over anything else because I'm now getting anywhere from 5m-7.5m a week from credit heist and once you can get all those credits from credit heist, it becomes so much easier to progress your other characters.