OP, some of the replies on here are harsh. Please don't think you're a bad mum. Actually, you sound like a lovely mum who just wants her child to be well fed and nourished, but you do seem somewhat stressed/overwhelmed.
I will agree with the other replies that she's far, far too young for this.
Take all pressure off mealtimes. Trust your child knows her own appetite. She could be coming down with something, not hungry, teething, tired, just doesn't fancy what you've made...the list is endless.
As long as she's growing and developing well, just go with the flow. Offer toast alongside what you're making (safe food with new food). Look at 'division of responsibility. Don't encourage, coerce, bribe, praise, scold etc at mealtimes. Don't mention healthy Vs unhealthy foods. Just offer food, tell her what it is and sit with her as often as possible. Talk about your day etc, ask her if she's done then clear away. Offer pudding/fruit/yoghurt.
It's stressful I know, when you've cooked a meal but do simple meals occasionally (cheese and crackers with fruit or whatever).
If it helps, I have one child who's a bottomless pit but limited diet (autistic) and another who eats a variety but somedays eats like a sparrow and other days, has loads (her favourite foods are eggs, broccoli and chocolate!). Both are growing well.