AT 6 months you don't need to go full on with solids, so no need to do 3 full meals per day if your LO isn't all that interested (mine loved solids so wanted 3 meals very soon after beginning but some will be happy on 1 or 2 little solids experiences per day), by 9 months you would likely see a need for 3 meals and perhaps between 9-12 months switching 1 or 2 of the day feeds to a snack and drink. I totally agree that you will feel like you are feeding all day long in the early days, it does get better though. In the early days they take a long time to eat (45 mins to an hour here) and spend time playing with the food which gives them valuable positive experiences too. I also worried about the amount of time spent feeding at that age until a fellow BW reassured me. There is huge educational and developmental experience with touching, smelling, squeezing, tasting, dropping (although I prevented that part as much as possible!) food so really it is a valuable activity just like playing with toys.
Also you don't need to leave 1.5hr between, I think most leave 1hr, so milk first and solids meal 1 hr later, this allows them to fill up on milk (best source of nutrition and calories) then build just a little hunger interest an hour later, tastes rather than 'meals'. Milk needs may still increase, that's fine, and gradually over time milk needs will level out and the additional hunger from being older and bigger will be met by increasing solids intake. Chances are baby will lead the way with this which is really helpful
At this age you can introduce finger foods so even if you like to give a puree/mashed meal at one sitting you might also offer a steamed vegetable baton or piece of fish or meat from your own meal at another sitting, this way you are not cooking a separate meal, LO learns to sit at the dining table with you as a family and learns about eating from watching you, this also helps as LO learns the tastes of your family meals which is different from household to household. Only thing to watch is to chop pieces into adult finger size pieces (ie not small pieces) and not to cook with salt, sugar or honey. I adapted my cooking and added soy sauce or salt etc after removing a portion for DS. Or with spicy foods i kept it quite mild took a portion out for DS then added more curry paste etc for the adult meal.
Hope this helps.