Since I have the stance that the feelings that led me to transition were there from the beginning, it merely took me a long time to figure them out and decide what to do about them, I don't really have anything to urge against this path in the general sense. For me this was something that I feel would have happened sooner or later. If I hadn't I truly believe that I would at best unhappy, at worst I'd have psychologically broken from feeling isolated and alone.
With that said, there are health concerns with hormones. Potentially increased chances of blood clots being the big one I watch for, which includes some awareness of high potassium foods. I luckily don't have much else on my radar. I'm not much of a medical person, so I just watch what I need, but not much expertise outside of that.
One thing I will recommend is to work with a doctor who can monitor blood work regularly. Personally, I'm not comfortable with the DIY approach both because of blood work monitoring and me not fully knowing what are in, or potential problems, with internet bought medications. I'm more comfortable deferring this judgement to my doctor.
One last thing on the medical side...talk to a counselor/psychologist/therapist. I can't speak for everyone, but I found this invaluable. I needed this time to talk through how I felt, read materials I'd not heard of, and talk with other transgender people in a support group so that I was sure that I both wanted and felt I was strong enough to transition.
As far as other struggles, nah. I like to think I became a very emotionally and intellectually strong prior to even telling my first person. My biggest issue was dealing with ingrained behaviors from having a giant wall/defense mechanism put up for so long. Three quarters of my life I didn't talk about and steered conversations away from any topic that might have led to me talking about how I felt about being what I now call transgender.
I've been very lucky with a supportive family, accepting friends and when I actually go to a religious function (like a wedding) there being an inclusive congregation.