I am days short of 4 years of being on E, and the effects do come and go in a wave motion. Your male breast tissue had the dormant milk glands highly compressed in a very tight little nodule that was almost too small to feel, and which you did not recognize for what it was.
You have seen party ballons that are 3 to 4 inches long when they are in the bag, blow up to twelve times or more times that length, well, your mammary balloon bag is open, and the blowing up is beginning. For a Cis woman, the process takes 5 to 7 years and she started out at age 10 or 11 with what you had a month and a half ago.
Your method of taking your estrogen does not matter at all, and heavier hormone levels will NOT speed things up. You are a growing girl, just like your mother, sisters, and maybe daughters will be or have been. Time is the real physician here and you will do what you are going to do over that time. We start time all over when we go on hormones, we do not enter a time machine to the future with high dosages. The 5 to 7 years time frame is realistic, but it does go by quickly one day at a time.
My development has been good enough, that two months ago I had a mammogram done on my breasts. A suspicious mass was discovered, and I had a needle biopsy done on it to see what the mass was. It turned out to be a benign fibrous growth, but I now have a small metal marker in my breast to track further development of that tissue. Be careful of what you ask for.