Once upon a time I thought I couldn’t paint birds, but then one day someone told me they thought my birds were beautiful. That’s all it took, and I began painting them all the time with confidence.
Same thing with horses, which I always found impossible until one day I accidentally got one right, and after that told myself I COULD paint horses, and with that more positive outlook found it easier to improve. They still are not easy for me but I’m getting there. Then last year a book publisher asked if I could do an entire book of horses… and I took a breath and said sure.
Seems that if I tell myself I CAN do something the failures are shrugged off as anomalous rather than the rule, and that encourages a positive approach to the next attempt.