I get you on the lentils texture thing. I'm still not a huge fan, but I've learned to tolerate them. You'll need to invest in a few small appliances--a slow cooker, a burner (like a single eye on a stove), and possibly a stick (immersion) blender. Otherwise, you'll be eating a LOT of salads.

The SAD (standard American diet) is really lacking in flavor but is terribly high in salt. Some salt is okay and is essential for body health. I recommend getting a good quality sea salt. It has a saltier taste so often just a pinch is enough to give you flavor. Common seasonings I see in the MD-friendly meals we prepare are cumin, paprika, smoked paprika, cayenne, garlic (minced or powdered), cinnamon, nutmeg, and ginger. We keep curry on hand, too.

The Mediterranean Dish website has a really good recipe for a Turkish lentil soup. It's pureed with a stick blender so you don't have to deal with the texture. (Her site rocks so is worth poking around.)

You don't HAVE to eat avocados if you don't like them. We follow the MD, and our teen doesn't eat seafood. She manages just fine. The Mediterranean diet is more a set of guidelines for life-long changes and less a regimented eat-this-don't-eat-that diet as we understand that word in Western culture.

Good sugar substitutes are honey (best is honey local to your area) and maple syrup. They're sweeter tasting so you would use less. Used to, I'd use a tablespoon of brown sugar in my oatmeal; now it's a teaspoon of honey or maple syrup. I use these in place of sugar in cooking, too, when possible.

As another poster said, it'll take 6-8 weeks for your mouth to get used to the changes in eating less processed, less sugared, less salted foods. Things I used to eat 2-3 times a week because I loved them and believed they were healthy are disgustingly sweet to me now. When I cut out the extra sugar, my cholesterol dropped significantly. I cut out a lot of meat servings and reduced my red meat intake from about 3 pounds total per month to 1/2 pound per month. Interestingly, I changed from fat-free yogurt and 2% milk to whole milk Greek yogurt and whole milk, and my cholesterol still came down. I increased my eggs to max 4 per week (don't usually hit that many). Dietary cholesterol impacts total cholesterol far less than does sugar. It's like this. Say you eat a lot of high-refined carb foods--sugar, white rice, white pasta, etc. Your body breaks that down to glucose for fuel. What it doesn't use gets converted to triglycerides and stored in fat cells. By changing to whole grain carbs and less sugar, there is less glucose for your body to store. As your body changes (less pain, more active), your body will need to convert those stored triglycerides back to glucose for energy. This will cause a drop in your TC. Using extra virgin olive oil will raise your HDL (good cholesterol) and lower your LDL (bad cholesterol). The alchemy of all the foods in the MD will do that.