you should of been running an AI during your cycle. Now your coming off cycle and going into PCT with elevated estrogen levels. Its estrogen that is going to keep you from being able to restart natty test production, as your brain sees elevated estrogen in the body and will not tell the testes to produce more test. this is why you need to run an AI during cycle and keep estrogen at reasonable ranges.
Letro is harsh but being your coming off cycle now and you didn't run an AI, its probably the best choice for you to use right now so you can get your estrogen levels down quickly so you can get your natty production back on as quickly as possible.
The other option is to stay on test at a low dose for a few more weeks and run an aggressive dose of an AI. That will give you a bit more time to acclimate to your gains. But if your getting off and going to pct now, then yeah run Letro