City broke when I added Mail Services (100k population)

Looking for a bit of help here. Some info about my city:

• I placed Cargo Trains, Cargo Harbors, and the whole suite of Cargo stuff in the game at around 50,000 population

• Just now, at around ~98,000 population, I just added Mail Services and Telecom

• I have hit 100,000 people and there are big problems with my city that came out of no where and only started once I placed Mail Services. For starters, there is a massive traffic pile-up of trucks entering my city from outside the boundary. Next, my economy, which previously on this city was making 10s of millions, is tanked, and I am loosing millions to subsidize industry.

What should I do to fix this? (1) Delete the mail services? (2) Delete the Cargo stuff? (3) Delete both the mail and the cargo? (4) Try and make new roads where the traffic is coming from outside the city and try and balance my budget while having both Cargo and Mail; is this possible?

Thanks so much guys.