Your doctor is ill informed or incredibly conservative. I never met a doc in Philly, with 5 medical schools including U of Penn, that said differently. The minimum TRT dose is 100mg a week. Your level is very low, the normal range is up to 1200. Once past your body natural range, your body stops making test on its own.

This is not a problem if your cycle is correct, blood work is done every 4 weeks, and you end the cycle. Supplementing up to 1200 is fine. Your doc may not be comfortable with anything past 550, but I am looking at a lab result and the range is up to 1200 (slight variations among different labs). Past that I know a lot of guys, including my former one (before he went to med school), who destoryed his body abilty to make Test on its own and has to supplement permanently.