I'm just going to say it because it looks like no one else will:
Dump this down the drain now and move on with your life.
Why am I saying this? Because after reading what you've done I can conclude that you're obviously not experienced enough to have made a beer worth drinking. Dumping in sucrose and extra extract to boost gravity without contemplating hop usage, fermenting at a very high temperature (70°F, are you serious?!), not having proper equipment, not knowing WLP099 is White Labs' Super High Gravity Yeast (anyone making a beer with that high an OG should know that yeast), etc.
I don't want to discourage you from trying to be bold and doing a "big beer", but you do need to have a better understanding of what you're doing before you invest your time and $$ into it if you want to be able to drink the results.
Saying all of that I'll still answer your original question: yes, you would need to add sugar (dextrose prefereably) during bottling, and most likely a bottling yeast since your primary yeast most likely won't be active any more. For my Belgian strong ale I use dry champagne yeast that I add with the dextrose while before bottling. Of course, I also use a liquid yeast starter for primary fermentation and WLP099 for finishing.
GL with brewing, and feel free to experiment, but do so wisely lest you only end up with undrinkable beer.