First of all don't worry! It can be worrying to read all the posts on this site! Some tips from personal experience. Don't worry about cosmetics they are fine here. The only thing you can't get is applicator tampons. I can't remember if they exist in Italy but if that is important, bring a load with you until you go home for a visit. Bring electronics with you. Bring USD dollars with you instead of Euros. You will find it really easy to convert dollars and you don't even need to go to a Cueva. I know quite a few people who will happily exchange their pesos for your dollars. I know them personally so I can always help you there. I'm sure your boyfriend will also have family & friends who want dollars!
Expect that your freight will take longer to arrive than you think. My company organised mine but due to waiting for signatures & notaries (say no more...) I am about to get my freight after 3 months. Your freight probably won't take that long but I would take more than one suitcase with you.
Clothes take them with you. There are many shops here but the clothes aren't so good. They are not awful though! Most stores cater for slim women.
You'll be surprised by how you will adapt. The only food Item I took with me was a 'bottarga di tonno'
. I think it can be too overwhelming thinking of everything. Ship some of your goods, bring more suitcases on the plane & pay extra. Take a few very small food items that are unusual to find even in Italy but ones that you love.
There are many apartments here that you can rent with furniture.
For Spanish lessons I can recommend a private tutor. I think it's better than classes. I think you will be at an avantage to learn the language despite the false friends in Italian. You will be much more interested in learning it once you are here. The motivation of wanting to interact with friends etc will take over!
Most importantly see this as an adventure! It's natural to be overwhelmed & scared. I was, but it's also exciting too. When you are old you will say 'at least I lived an interesting life' ha ha!
PM me if you want to ask any more specifically female related questions!!