It sounds like you need to find a local suspension shop where you can ride the bike in and they'll take the suspension off, respring/revalve the forks and shock. If there's no local shop there's few companies that you can send your forks and shock to and have rebuilt for your weight and riding style, such as Race Tech, Cogent, and Daugherty Motorsports. But if you're not a DIYer you'll need to take the bike to the dealer to have the suspension taken off and sent out. If you're going to do this it might be better to buy a rear shock and fork internals and have the dealer just install them. This might be the easiest solution, research aftermarket shocks and pick one, research fork options, most likely a heavier spring for your weight, and possibly a cartridge emulator such as Race Tech, Ricor, or Cogent. Take your bike along, with your new upgrades, to the dealer and they can put them on in a day.
2009 Wee Strom ABS (current)
1987 Harley Low Rider Sport (current - with 205K miles)
2009 Aprilia Mana 850, 2006 SV650, 1984 Yamaha Virago 1000 (all sold)
Silver Strom Club Member #11
Wee Farkles: Russell Day Long Seat, Madstad with Moose Adventure Shield +4'', SWMotech Centerstand, 1'' up & back bar risers, Givi XS308 Tankbag, Aprilia mirrors, Framesliders, Fenda Extenda, Elka Shock.