Like Gene stated you will need a bit more titration, but eventually you should be able to find stability. When I worked at the pharmacy I got to speak with a handful of guys who did the cream/injection combo. Most to help with DHT after long term finasteride, and others maybe because they liked the effect.
The goal with topical T is to have a higher concentration so that you apply less, 200mg/ml Is usually the highest. Ask for a versabase cream which is the same carrier that compounders use for vaginal application, it absorbs into sensitive tissues very well and wont dry your sack like alcohol based gels will.
Start slow and low with the topical, and increase after confirming labs and if needed. 25mg is a common starting dose that I witnessed, probably depending on how much you are injecting. Follow up every 4-6 weeks until your levels are stable, and be sure to add DHT to the panel.