If there are no policy flags on the account, and impressions are not increasing, it would suggest you are losing auctions. If that is the case Increase your bid/budget could help, so you could try increasing it for a few days. You could also be bidding on highly competitive keywords, so it might be worthwhile to try other keywords. Quality score can also drop your positioning and with highly competitive keywords/audiences make a big difference. So try making sure your landing page and ad messaging is very relevant to your keywords and targeted audiences. Those are some things to try.