Firstly, I've SO been there and done that with the forever feelings. It IS hard. If he won't take a bottle, have you tried other ways of getting liquids down him? Eyedropper, cup, sippy cup, my son always like mini dixie cups, even a spoon. Your breast milk has all the iron he needs, as well as every other nutrient, for his first YEAR of life! Lots of children (around the world) only get breast milk for their first TWO years, and this is FINE. You can ADD calories, but he's getting all the nutrients and water he needs, rest assured.
Secondly, you need to take breaks. Dads, grandmas, sitters, neighbors, aunts etc. are all capable of doing some solid feeds, or cup feeds or whatever, for a short while. Go out and see a movie, take a short hike, go drink tea at starbucks. Give yourself a bit of time to be YOU. 6.5 mos w/no break due to feeding is HARD.
Thirdly, he's not actually going to go to kindergarden with the breast in his mouth LOL! He's going to take to solids eventually. I've heard that children need to be introduced to foods 7x before it's NORMAL for them. So keep offering, don't force, just let it happen. He'll get there. I PROMISE!!! ~~~HUG~~~
Lastly, the kinds of foods I used for my kids were squash, sweet potatoes, and carrots initially (steamed, smashed and strained), nothing at ALL added. The textures are funky, and it will take some getting used to for them, but you are RIGHT - he is too young for any of the solid foods. He will choke on them, they are not safe. GOOD INSTINCTS! :D Just keep working with what you're doing, keep the foods simple, and he'll take to them ... or you'll start him on kentucky fried chicken lol! Good luck mama!