here's the thing. you probably can't do this yourself very well given the areas you're talking about. not sure how you're planning to reach your back. you would have to ask someone to help you i would think in any case.
your temporary options are : shaving, waxing, trimming, depilatory creams
permanent options are : laser and electrolysis
temporary ones are relatively cheaper, though if you're talking about major areas, it would probably make sense to go with permanent since you'll be spending a somewhat considerable amount of money anyways. permanent methods require a commitment, so that's something to consider.
can i ask why you're trying to avoid professional clinics? if it's a simple case of embarassement, i really urge you to rethink it because that's what these people do each and every day. they have seen everything, every type of hair situation and treat everyone in a very professional manner. many people working at these clinics have experienced excessive hair issues themselves and are easy to relate to. it's not much different than going to any physician for a treatment for anything else. they're medical professionals and it's their job to be professional and understanding.