Bosco,
you need to stop beating yourself up! You are a great Mum and the fact that you are persevering with b'feeding in spite of how hard it is is amazing. I struggled with b/f for 8 weeks and DD is now 100% bottle fed. Yes, I felt a bit guilty, but it just didn't work out for us. I got to the point where my stress levels were really interfering with me enjoying my daughter.
The most important thing is that you love and nurture your baby. However you choose to feed her is simply a choice you will make - there is no right or wrong - just what is best for you and your baby, Good luck