Very quickly he will get more proficient, it's very early days. You'll find that textures which make him vomit now are fine in a few weeks' time. At this age it's really just tastes, so I would offer some aspect of what you're eating or an easy alternative such as a banana or pouch or pre-prepared food. You don't need to worry about nutrition as such as he is still getting almost all of his nutrition from milk, it's more about trying a variety of flavours and textures.
So for example for a tuna sandwich I might offer a piece of toast or some sticks of cucumber or peppers. For a salad, cucumber or peppers again or tomato slices, cold cooked chicken, hard boiled eggs, sticks of cheese. Or just do a jar or plain Greek yoghurt or something I've made previously.
You could double or triple the AK recipes to make that cooking session last longer. I also would just make really simple purees/mashed or blended bits of our meals and chuck them in tiny pots in the freezer so it wasn't extra effort. If you freeze things then you can pick out different ones each day, rather than feeling that you need to use up everything you've made ASAP. I used little pots by Nuk (I think they are actually AK branded) so they don't take up much space. You can then microwave them in the pot and transfer to a bowl. Or some people freeze individual ingredients in ice cube trays - a tray of sweet potato, a tray of chicken, a tray of carrot, a tray of plums - you can then pop out the cubes into labelled sandwich bags and mix and match. One day potato, chicken and plum. Another day pea, potato and carrot. Another day chicken and carrots. Just pop out 1-2 cubes of each flavour, place in a bowl, microwave and combine.
Are you doing 3 meals a day already? You don't need to yet, I was only doing 1-2 meals at that age, it's much easier to get variety that way, so you do one "dinner" type meal and one breakfast - baby porridge, weetabix, toast, yoghurt, or fruit (BLW or puree). Nobody minds if breakfast is the same every day (and you don't have to offer it at breakfast time). Once they got proficient at self-feeding I added in a "lunch" type meal (cut up cold salad veg, toast, strips of cold cooked meat/cheese, eggs, baby "puff" crisps, breadsticks etc) This means you have to do less thinking up of meal ideas and your homemade meals will last longer too.
However, having children does just kind of feel like cooking for them forever and ever 😅and they are rarely appreciative, so it's a good idea to get into the mindset of not attaching too much emotion to it - spend time and energy preparing stuff you would like, and don't be afraid to use convenience shortcuts whenever they make life easier for you. It can be really easy to pour your heart and soul into food and then it's frustrating when they don't want to eat it or are fussy, which can then feed into an unhelpful cycle where you get anxious or frustrated at mealtimes and that puts them off even more.