I would buy a new water heater. If it is leaking, bursting usually isn't that far behind. And trust me, you do not want it to burst. Plus for what you end saving by not paying to heat all that water that is leaking, it will pay for itself in no time.
You mention having your own water; is it well water? If it is, and it has high mineral concentrations, you need to drain and run high pressure water through once a year at minimum; the minerals tend to settle and cause blockage and rust. Learned that one the hard way:-(. If it is over 5 years old and you do have this mineral issue, your heater may already be rusted and cracking at the bottom.. Would call a plumber to check it out.