Tbh ,,I'm to embarrassed to say what I'm eating,I know it's bad .
I get stuck eating the same foods for each meal ..( autism)
Currently I'm living of corn crispbreads and salad ,
But I go through stages of liking tofu and beans ,I just don't seem to be able to maintain a variety of foods ,I'm always limited to about 5 things a time for weeks .
So very embarrassing,but I am trying
Don't be embarrassed. Autism can make food/eating very difficult.
I do think you may be lacking in quite a few things though based on what you've said, so it's not just protein that needs addressing.
As you can eat and have liked tofu and beans in the past, I'd try to get in the habit of having those every day in your diet. That will increase your protein as well as things like calcium and iron. Can you add them to your salads? If you can make those 2 things a habit, then add something else, like almonds or walnuts. Hopefully if you introduce things that become part of your daily routine, you can end up with more foods that you eat every day.
I do eat a good variety of meals/snacks but things I tend to eat most days are porridge with oat milk, tofu, beans, nuts, seeds, fruit and veg, some wholegrain rice, a protein yogurt.
You said you take vitamins, do you take one specifically for vegans?