24 here. I have the same worries and fears. I spent ages 15-22 in long-term relationships. Since the dramatic end of that period of my life, I've been focusing on taking care of myself and creating a space in which to be comfortable, nurtured and happy, and that's gone quite well, but I seem to be no longer capable of dating. I tried it a couple of times in the past few years, and every time it's been a ridiculous sort of fiasco of awkwardness, halting sentences and jumbled thoughts that deteriorated within 3 months. It's definitely a debilitating fear of intimacy, based on past experiences. I am also constantly afraid that I will be left by the wayside, or cheated on.
I don't really worry about being alone in the future, but I think that's because I've made a concerted effort to be ok with being alone... though sometimes I still do get quite lonely. Maybe my lack of fear in that department is also based on the fact that I don't think about the future very much. If I do find myself legitimately alone someday, I will probably get a dog. If I then still feel a need to become friends with a human, I will go to dog parks and meet people. Or I will join a community league, like ultimate frisbee or something. Failing that I will move to a bigger city and find some weirdos to hang out with.
Also, I live in NB, Canada! What are the odds? You should PM me!
_________________
I(ntroverted) iN(tuitive) F(eeling) P(erceiving)
AQ = 35
EQ = 31
SQ = 48
Your Aspie score: 160 of 200
Your neurotypical (non-autistic) score: 53 of 200
You are very likely an Aspie