My ex contacted me not long ago, what do i do now?

hello,my posts get few replies so i thought i would put it all into one, i really need some help or advice as i just don’t know what to do, my ex girlfriend broke up with me in august 2014 after being together for 7 months, now that might not sound like much but we knew each other for 2 years as friends. after helping through a rough time with a bad relationship, we had become attracted to one another, she told me she loved me and i loved her too, when she ended her bad relationship i helped even more so, she told me she wanted to be with me but it didn’t feel it was right just yet, so we waited and when the time was right, we became a couple. 5 months go by as the relationship is the best thing to happen to me, i’d never been so happy, but during this i was struggling with family life to such a point i argued with my aunt almost every night. (i lived my guardians rather than my parents) in may 2014 i went to spend a week with her, she wanted me to spend a week with her, just us. i said i would and plus the time away from home would help. i lived round the corner from her, that was one of the benefits of our relationship being that we lived so close together. the week with her proved to me that our relationship was going long term. i was so happy. but the night i went home, me and my aunt just argued, practically as soon as i went in the door, the result of which being that i was kicked out, the next day i was working at shop and i told her that i was leaving the next day as told her about the argument. 24 hours isn’t enough time to explain. but we thought it may be temporary and that i would come back. i was lied to by my family about that.
now i live over 100 miles away with other family members. so our relationship became long distance. it tore me up. i blamed myself constantly and that really affected our relationship, she felt restricted as i began to say thing like her ex did but in truth i was hurt so much and i just wanted to be with her, and eventually, it ended, i was low, and when low, i mean that kind of low, i begged, friends told he cheated on me, i was so confused and it made things bad with my family that i’m living with. i tried talking to her but i messed up. so i moved forward, which isn’t moving on, i got a job and just worked but i thought about her everyday, in November of that year did message me, and we had i nice chat, i didn’t bring anything up, she hasn’t spoken to me since. it’s now march 2015, i’m hoping to start a new job soon. but in regards to her, i still love her. she also has job and hoping to go to uni. i’ve reached a point where moving forward can only go so far. i want her back but i’m afraid, it may be too late.

she me messaged me last week which was sudden and out of the blue, it wasn’t a long conversion but happened nonetheless which is why i need some help with this.

however I have been given a more clear picture of what had been going on since the break up and possibly the real reason why. I found out from a friend that she may have cheated, now I knew there was a possibility since I heard just after the break up she may have kissed another guy, but I denied it, but since she contacted last Wednesday I decided to speak to a friend about it, and that when found that the cheated may have been more true than false, as a week before we broke up apparently she was eyeing another man, it confirmed my fears and my friend did why would you get back with her, and I said “Like I said, I was under stress, I’d had been lied to by family, they told me that the living circumstances would be temporary and I would come home, so you can imagine how I felt, plus being away from Em tore me apart, it still does, I hope I wasn’t controlling, if was then I’m sorry about that, I feel like she is my soul mate you know, that my actions and behaviour were do to stress, but now, I am strong again to the most part, I really need to tell her this, I mean after all that happened with Dan, I just knew I was meant to be there for her, to comfort her, being far away takes that away, I hope she can one day feel that she can invest in what we have and I hope she can give our love just one more chance, is that too much to ask?” This was my exact message to friend. I do love her, and I can forgive her, as far as I know she broke up with the guy she was with after me not long ago, so what do I do? I thought of writing a letter to her, because that can’t be ignored. but my friend said that maybe an association to her ex before me as he wrote a letter and it was very hurtful, so there are few options for me, it’s driving me crazy and i’m losing sleep and sanity over this, so please, can anyone help?