You could have a flooded utility conduit, freeze thawed line converter into the house, partially severed connection, fully severed connection and your DSL is being routed through a limited bandwidth pipe, damaged exchange, or any number of other combinations of faults. I would report it to whoever your Telco is
(forget about reporting it to the ISP - unless they are one and the same, usually gets you patronised by some snotty 17 year old
) and ask them to test your line.
I shant be crying too hard for you though, out here in the wilderness of the UK badlands, all I can get is 512K. So seeing someone with 3Meg brought back down to my level is rather satisfying muhahahahaha