I just want to say that everything you think and feel is perfectly normal. You do exist, what happened to you isn't your fault and you handled it with best personal resources you had at the time. You can't do anything better than that can you.
From what your telling me, there were more instances than three but a few more other things when your sister was around. The reality is your dealing with two pretty damaging situations. Your first abusive relationship and then this family friend. That's a lot to deal with.
I'm wondering, do you live with your parents and if so do they know what happened? Has anyone told this guy they don't want him ringing or coming near the family anymore? I don't think you should have to keep dealing with the fact that he might ring or come around. If he calls again some someone answer the phone and tell him off.
I can see that your angry and that your holding your feelings inside. I can see that your beating yourself up about not dealing with it differently. Anger is a normal human emotion. Women I think are socialised to not express their anger it's seen as unlady like. But feelings are normal. It's what you do with the anger. Sure you don't want to wind up all bitter and twisted about this



Sometimes it helps to write in a journal, lots of people use them to get their feelings out express themselves. This might help you too. It also helps to write down what happened in any way that is comfortable for you, get it all out.
It's interesting because sometimes we think we are strong by holding things inside, not getting emotional, not letting our feelings out. But I actually think this makes things worse.
I'm thinking that maybe your interested in learning a few things about communication. Like assertiveness skills. I really liked these and they helped me to feel more confident in communicating with others. They teach you things like how to feel confident in saying no, how to speak your mind. Try doing a google search.
I see that you are a trusting and kind supportive person. But maybe too quick to trust. I think being supportive is a really good trait to have as a person. But I think being careful of getting to no someone very well first before opening up or letting them open up to us is a good strategy to have.
It's totally natural that you feel uncomfortable around men, especially when they are behind you. I think that is all normal and over time you will start to be less jumpy in those kind of situations.
The other thing that really helps is learning to be physically confident. Walking around with a don't mess with me kind of walk. I don't mean you have to go around with a mean look on your face or look like your going to punch the lights out of the first person that looks at you. Self defence classes are really good for that. Do you do much physical exercise? are into sport? maybe get a friend and try out some kick boxing or , make some enquiries about a women's self defence course one where you don't have be turned into some black belt ninja. Unless of course you want you. It's important to know that self defence isn't about preventing sexual assault but it's about giving you a sense of self confidence about yourself.
Sometimes is sucks being a woman. I can feel sometimes that each day we walk a gauntlet of where we are having to avoid men staring at us, perving on us, flashing us or yelling out some kind of rude comment, or advertising. It gets tiring doesn't it.
Hang in there your doing great. Write back if you want to chat more.