Sorry you are having such a difficult time at the moment.
No-one on here is going to tell you whether or not your ds has autism, there's no way any of us could possibly know. Honestly, there are many reasons children might be displaying the behaviours you are describing and they are not all as bad as you might think.
You are doing absolutely the right thing going to your doctor to discuss your concerns though and hopefully they will, if necessary, refer you on to someone who can assess him for any potential problems.
As for will he be ok, well it's another tough one that. If he does have a developmental problem then honestly, in all likelihood yes he will be fine and after a period of adjustment, so will you. Things might not be the way you planned and expected them to be, but that doesn't mean they can't be good, but different, iyswim.
Just go to the appointment, armed with a list of your concerns about your ds and be honest with him about why you are there and what you want to get out of the appointment. If you are concerned about the possibility of autism, perhaps you could try visiting the Autistic Society's website and do a bit of reading around the subject.
You are in a tough situation at the moment, worrying about what might be and not knowing is really hard, but your ds is really lucky to have you for his mum, as you are obviously on the ball enough to notice potential problems and proactive enough to do something about it. Having parents who will fight for you is half the battle.