SharePoint CSOM Check if Folder Exits

FolderCollection folders = oList.RootFolder.Folders;

                String folderUrl = "/Lists/TestList/" + DateTime.Now.ToString("MMM-yyyy");

                IEnumerable<Folder> existingFolders = clientContext.LoadQuery<Folder>(folders.Where(folder => folder.ServerRelativeUrl == folderUrl));

                clientContext.ExecuteQuery();

                Folder existingFolder = existingFolders.FirstOrDefault();

                if (existingFolder.Name == DateTime.Now.ToString("MMM-yyyy"))

                {

                    //add item inside folder

                    var itemCreateInfo = new SP.ListItemCreationInformation();

                    // need to specify full path after site domain            

                    itemCreateInfo.FolderUrl = siteUrl + "/Lists/TestList/" + DateTime.Now.ToString("MMM-yyyy");

                    ListItem oListItem = oList.AddItem(itemCreateInfo);

                    oListItem["Title"] = Environment.UserName;

                    oListItem["Model"] = model;

                    oListItem["Count"] = count++;

                    oListItem.Update();

                    clientContext.ExecuteQuery();

                }

                else

                {

                    //Enable Folder creation for the list

                    oList.EnableFolderCreation = true;

                    oList.Update();

                    clientContext.ExecuteQuery();

                    //To create the folder

                    ListItemCreationInformation itemFolderCreateInfo = new ListItemCreationInformation();

                    itemFolderCreateInfo.UnderlyingObjectType = FileSystemObjectType.Folder;

                    itemFolderCreateInfo.LeafName = DateTime.Now.ToString("MMM-yyyy");

                    ListItem newItem = oList.AddItem(itemFolderCreateInfo);

                    newItem["Title"] = DateTime.Now.ToString("MMM-yyyy");

                    newItem.Update();

                    clientContext.ExecuteQuery();

                    //add item inside folder

                    var itemCreateInfo = new SP.ListItemCreationInformation();

                    // need to specify full path after site domain            

                    itemCreateInfo.FolderUrl = siteUrl + "/Lists/TestList/" + DateTime.Now.ToString("MMM-yyyy");

                    ListItem oListItem = oList.AddItem(itemCreateInfo);

                    oListItem["Title"] = Environment.UserName;

                    oListItem["Model"] = model;

                    oListItem["Count"] = count++;

                    oListItem.Update();

                    clientContext.ExecuteQuery();

                }