Outlets are half voltage and/or don't work
A picture of the main panel would be helpful. But it sounds like at some level - either in the panel or possibly before the panel you "lost a leg" - that would result in 240 --> 120 and 1/2 of your 120 --> 0. If that is really the case, CALL YOUR UTILITY COMPANY as it can be a very serious problem. The big question is whether the problem is caused by something inside your house (for your electrician to fix) or outside (which the utility will fix, usually quickly and for free).