Stuttering

When this game released I was one of the few players that actually had no issues what so ever on pc. However as of the last 2 days (after the more recent patch) I have been experiencing nonstop stuttering/lag spikes in multiplayer matches. I do not use third party software and I have no understanding as to why this only developed into and issue more recently, and not on the first/second day of the game. How can I fix this, or how can I even begin to identify the problem?