Hello
I applaud you and commend you on the effort you are making to overcome your symptoms!

) Please continue to do so, it does take a little time to do it the 'natural way', but with continued diligence you will definitely reap the rewards you wish for.
As for SSRI treatment, it is not something I completely disagree with, but I really only advise it as a very short-term thing, and only in the worst of cases. However, as you are a nursing mom I would definitely recommend you don't give in to the skepticism/pressure you have to deal with to 'take the easy way out' with these drugs. You would definitely be risking passing the SSRI through your breast milk to your little one, and this can be dangerous for your child, despite what the pharmaceutical companies and other ill-informed people would have one believe.
In answer to your question about the safety of L-Tryptophan while nursing, I can give you this info.:
Thomson MICROMEDEX
http://www.micromedex.com/ states the following in their literature about L-Tryptophan:
Side Effects and Precautions:
"Pregnancy - L-tryptophan has not been shown to cause birth defects or other problems in humans.
Breast-feeding - It is not known whether L-tryptophan passes into breast milk. However, L-tryptophan has not been reported to cause problems in nursing babies."
You can read the full report here:
http://health.yahoo.com/health/drug/500179/overview
Personally, I have been giving my 7-year old 100 - 200mg L-Tryptophan every once in a while, and he has not had any adverse reactions to it, in fact it has been very beneficial for him (he has suffered with chronic illness). It not only maintains proper brain function but it also stimulates proper immune function amongst other things. L-Tryptophan is an essential amino acid and can be found in quite a number of food sources, the most well known being Turkey, some legumes and warm milk. L-Tryptophan has a breakdown process once it enters the body, and so I think it is unlikely that L-Tryptophan in its true form would be deposited into your breast milk, but even so, I think that any L-Tryptophan that might find its way into your breast milk would be very minimal, and quite healthy for your little one.
Incidentally, L-Tryptophan is an ingredient which is included in most good infant formulas. Similac Alimentum, Neocate, Enfamil Pregestimil etc. are a few of the brand names. So naturally it is safe, and beneficial for infants and children, but I would not necessarily supplement it in a healthy child's diet, unless necessary, if the child consumes a healthy balanced diet. Usually a nice 1/4 to 1/2 glass of warmed milk, with a drop of honey in it (not boiled) every once in a while for a child before bed-time is more than sufficient.
If I find any more sources re. L-Tryptophan and nursing I will certainly post it here, as it is a good and very valid question. In the meantime, your local compounding pharmacist (even your midwife if she is inclined to the holistic medicine approach) might be better able to give you more specific information on this topic.
All the best,
Anthea