I dont think bitcoin is under attack maybe the reasons why its because of heavy traffic or congestion. I also encountered this too long to be confirm in my wallet, blockchain problem that took 2days confirm in my wallet. I think its trhe volatility price of bitcoin that most encountered this problem.
The attack is the traffic, someone are doing a lot of microtx just for increase the traffic. I don't know who or why but it's real. For now, the best solution probably would be increase the blocksize..