1995 Chevy Suburban faulty ignition?

I have a '95 Suburban, with a six month old battery. Over the last few months, the car has started "sluggishly", with a hesitation almost like a near dead battery, but then when it kicks over, it starts right up. It's been getting worse until now it won't start. Battery appears fully charged, and the cables are good. The starter works great but only after it begins to "kick over". I think it's the ignition switch, but thought I'd ask an expert to see if this can be a problem with this year Suburban. When I turn the key, it clicks, again as if the battery were dying, but the headlights are bright, even when turning the key. Thank you for your suggestions!

Also, if it's the ign, is this something a back yard mechanic can fix?