2 times comeback from Fanta. what to do?

Yes, this is my second time comeback from Fanta after facing many despair.I have planning to leave it forever before, But I can't. I don't know why just can't. And now after second comeback, I've seen many people have 7* and 8*. But right now I only have:
3 3*
26 4*
9 5*
1 6* (and its Bristol)
1 POT
0 TE
I was planning to go trading, but all my cards are worthless:( , plus there are 8*, which 5* isn't worth anymore even 6*. If you have some plan what to do, please let me know  

(Right now I was planning to get 6* as much as I can)

To be honest, you're in quite the dilemma.

The easiest way for someone like you to gain some 6* is by obtaining TE and participate in events as harder as possible. Attempt to get the easier rewards and sell all gods at a potion per set. Once you have ten potions/TE, focus on key 6*, starting with cheap ones then going for more diverse targets.

Several NeoArtCore 7*s are now cheaper thanks to the Challenger Packs that increased their numbers. Finding one for 200 TE or a bit more(cheaper if with pots) shouldn't be difficult.

Just remember, pateince and strategic grinds are the key. Invest, then rest. Invest, then rest. The road is long, but you'll reach it.

For some motivation: i took a full year to obtain a rare 7* from my dream card list that costs more than 800 TE, and i only spent sparingly on a few events (around 5 over said year).

is it still possible for selling 4*/5* unit for TE/POT? cuz I've a lot of them.

If the 3*, 4* & 5* we're from a while back, they might be rare thus may offer a substantial value. Certainly is worth checking out.