Did you post your arena team and their gear? I remember chatting on your last sets of posts. In this post , I recommended farming 6-6 and 6-7 in campaign to get Rare Speed Set gear to get your Speed Lead, Lyssandra, faster than the 250 you were stuck at. 

How went the last week of farming Brutal and Nightmare Campaign? Did you get any good rare speed gear, with speed substats? Have you been running it at all?

This game is not a sprint in any way, it is certainly a marathon. Would love to help, but it seems the big thing your game is missing right now is food farming and gear farming.

ive been playing my main account since christmas. On almost everyday and ive done ALOT of farming. ive made it 3/4 the way through silver 4 i get ur pain tho for a while i was stuck in silver 3 with no hope of getting to the next tier so i farmed spider for better banners and got a sacred shard that gave me roxam. im now close to gold 1. Just give it time and keep farming youll get there. : )