Confused about amzon ads

Friends….i wanted to push sales of one of my ASINs which has lost track over the past few months. I used he10 and identified some 25-30 high search volume relevant keywords. Create a focused campaign with high bids. What i observed is that i am getting high impressions but low ctr of around 0.20%. some 7-8 keywords have made progress among the top 50 competitors. Spend has increased by almost 5 times without much increase in sales. All of this happened within a week. I have increased bids almost 3-4 times during this period and not touching the highest bids. Few questions

1) What is the right ad approach to push up sales for a languishing sku ?

2) How much time should i give for sales to pick up ? Is a week too less for this ?