That said, let us look into the most probable causes.
1. Wherever your appliances are plugged into, it is also on the same line as the lights. This could cause the dimming and power surges. Electricity will follow the path of least resistance, which is always the largest power consumer in the circuit.
2. The main line that feeds your house is undersized for your total power requirements. You mentioned the inside box but not the outside box. Is the wire coming from the electric company and feeding your panel boxes large enough to support your requirements?
These are the two items to address before you go any further. Begin with #2.............
That said, you seem to be implying that this problem has only surfaced recently. Is that accurate? Has anything, electrically speaking, changed in the same timeframe, like new appliances, circuits (besides the one new breaker), or other electrical work? How old is your home? Wiring? Is your service (main) line above ground or below? Has the electrical company been doing work in your area, like adding service for a new development? Do you know if you have a third (ground) wire as part of your home‚Äôs wiring? Has there been any plumbing work done on your home recently?
I‚Äôm not disagreeing with the other responses you have received, but there are other possibilities that may require a look at the wiring in your home.