How to fix copper pipe leak?

I have a 1/2" cold water copper pipe leaking in unfinished part of basement---it is hard to fix as there is a 3/4" hot water pipe crossing under the leak--which I think caused some of the problem. My son (I am 69 yr. female) is coming next weekend and will replace it. Until then he told me to cut garden hose and fix it---that worked with clamps--slight drip--but last night it stopped working. The only hole I can see in the pipe is a small one on the bottom of horizontal pipe--I think it started leaking again because hot water pipe caused the area around hole to give. I also had to wrap the top and bottom of pipe with hose to stop leaking--just the bottom didn't work. I am afraid to use epoxy as it will adhere to the pipe below it. Last night I bought a repair clamp with rubber gasket---it didn't work at all--I am not sure--but water seems to go up the sides of rubber and drip from the top. Any ideas would be great as I have to keep turning water to house off and on.