Emma - don't worry too much, they aren't all bad. Like you I was 38 when I was diagnosed and have been on Arimidex and Zoladex for nearly 7 years (had a little tamoxifen holiday for a few months, developed DVT and had to go back on the AI's).
The side effects for me in the early days were quite small. Bit of aching bones, tired and stuff, but nothing that I wasn't used to after chemo and radio! They did get better and I can honestly say that I was fine up until I had to go back onto it after the Tamoxifen holiday. My hair has thinned a lot and my nails suffered, but fingers crossed my nails are now fine and the hair seems to be coming back.
I'm off for my monthly stabbing later today........after all this time, its less of a problem than the dentist :).
Happy to talk more if it helps, good luck xx