Angel - don't be too hard on yourself. It is never easy being a parent.
My son is also fussy about his food, though he loves his porridge and fruits, he is not particularly fond of milk and his egg. So although sometimes he scream and protest, i still force him to finish his milk. Almost everytime have to kap his legs, hold down his arms and force him to drink ... he know got no choice then he docilely finish. (btw, nothing to do with milk powder, or milk bottle.. breastmilk he also liddat)
I know it sound very jiak ark of me, I also heartpain when he scream and cry, but wth, he gets fed and judging from the last time I carry him (now almost cannot carry for long liao, at least got 9 kilo)
I told myself, already children need discipline, let alone babies. They don't know what is good for them at their age, so sometimes we have to do what is best for them.