J.D.
I have 3 children, 14yrs, 5yrs and 8 months. Each breastfed. For each I started solids around 6-7 months. With our 3rd however she suddenly started having constipation about a month into it. As a result I just stopped feeding her solids and switched back to breastmilk only. What I re-discovered, which I wish I had sooner (like 14yrs ago!), is that babies don't really need to eat solid foods at this age. Getting close to a year they begin to need foods for the added nutrition, but not until then. I thought feeding food was more about her needs until I stopped and realized that it had more to do with my premature excitement over her entering a new stage. So, my new advice to mom's is to hold off on solids for as long as possible, eat a lot of healthy food, and nurse your baby as frequently as possible! They have their whole life to be eating food, and so short a time to be solely breastfed. Why not let them have it for as long as possible? Breastmilk is a super food. I am not sure what could be healthier.
As for the doctor giving you bad advice about bedtime eating... Breastmilk digests quickly. Your baby is surely hungry at night. To not feed him would be cruel. My 8 month old nurses all night long, and sleeps with us so there is no problem with me waking up fully to do it. There is no crying, she just squirms a bit, and does not wake anyone up.
Just remember, babies only need us this much when they are very young. Having a 14 year old now, I can tell you that you should be doing your best when they are very young so you will raise healthy children, and have fewer regrets. You should have more confidence in yourself, and listen to your doctor (who by the way has probably had very little training in breastfeeding, and nutrition) less.