relationships

Hello My self and one of pps have decided that is would be really nice to get to know each other a lot better he wrote to me saying that he feels that he has feelings which i have to admit there is something about him that makes me me feel so very good . I do care about him but on a different level to my other pps .
I am not sure what makes me feel this way I have written back telling him that I would like to see where this goes weeks ago but feel very scared at the same time .
A relationship has to start some where RIGHT ???? It just so happens I am in a different country and doing it by lots of mail .
Our letters are becoming more and more frequent at first it was once a week now its almost every day.
I have not fallen for his words but for the person he writes about and he says the same for me i have been totally upfront and honest about who I am right from the start .
But with this pp things got personal very quickly and although with my others i ahave a policy that somethings are just too personal and our letters are friends only but with this pp things became differant .
But with this special friend I really did open up and it felt right i cannot explain it just felt natural to do so he also felt this way too .
I feel very confused about the whole thing I did post a month or so back and i did take all of the advise i was given on board.
Our letters have become so different and now it looks like this is what we really want
We are not in love but feelings are starting to form for the both of us i am still at a lose to how this can happen because its through letters but it has .
I do realize that this will not be easy he has 4 and half years left for one and relationships in the free world have ups and downs and are not always easy so i know this realionship will be so much harder but this realionship does we both think have potenial to really grow .
We also have never met but we are planning on doing so may be march or april money is tight so its save save save from now on we want to be able to have regular phone contact but at the moment because of my personal circumstances thats almost impossible although my son is going to pay for phone calls next month over the holidays as a Christmas present which he has already arranged with my pp
Please can anyone one give me any advice good or bad I almost got to the point today where i didt write back then i wrote to say this is silly and impossible but didt post the letter.
My son thinks I should follow this through he thinks its a good thing but i am his mum and he just wants me to be happy we have talked because he picked up on things that i had said ..
Felling rather stupid as I think i have answered my own question but i do need to know is it too early for feeling to come into things or again is that a silly question too . All we both want is to see where we end up on this but what scares me is the love word I dont really want to say this to a man i cant be with he does understand this but laughs and says if it happens then it doest matter if i dont say it he will know.
He thinks its gone beyond the point where we can be just friends and cannot hide this from me and also does not want to hide this he wants me to be there in his life he also said if we had met in the free world things would be different but we didt and sometimes things have to be done in a differant way because circumstances force that . He feels it is perfectly normal . But also has said he cannot understand how we had such an impact on each other he just says two people just sometimes click nothing abnormal in his eyes .We also realize that although we know so much about each other already there is so much still to find out and we are learning a lot more as the days pass but i do also know that this takes time as with any relationship.
Thanks guys for listening
Flower x