from what you've said, he does seem to have a lot of anger and control issues that need dealing with, (as well as some stuff around respect and personal boundaries, and thats for a start!) and which make it unhealthy (both mentally and physically) for you to be in a relationship with him, at least until he does resolve them fully.
when he has got help, and when he's worked through stuff and maintained what he's learned for at least 6 months (or long enough for you to feel really safe), you can always re-assess the situation, and get back together, if you both want to, but i'd definatly advise against being with anyone unless you feel safe, like you can trust them, that you are respected, treated kindly, and that you are an equal partner in your relationship.
two things that come into my head: that you need to put yourself first, and i know how hard that can be- but you are responsible for your own wellbeing (and that of your pup) before anyone elses. right now, you're at risk of harm, and thats got to come first. also, that you need to come to understand that you can't change or fix his problems or behaviours (it seems you've realised this, which is really positive) so please don't continue to enable him to behave in an inappropriate way with you, its not fair on either of you, for you to reinforce this behaviour as being acceptable by taking it.
it'll be scary branching out on your own, but i think it'd be scarier to find yourself in a horrendous relationship with this guy, with no confidence, possibly unwell, possibly with a kid, and with what feels like no way out, a few years down the line. there are lots of sources of support available to you, if you need help moving on from this relationship, so make use of them! look online for charities offering support to women leaving abusive relationships in your area, and don't feel that because he doesn't beat you, you don't apply as an abused partner- you do.
if you need to, get help to move, arrange to get the locks changed, and/or consider letting the local police know the situation (that you're leaving an abusive partner and that you'd like it on record for your safety) so that they have you in their files, and so that if you call on them for support should he do anything stupid (eg: end up banging on the door at 3am drunk) they'll be right there and know the background, and back you up without your having to expalin everything on the doorstep when you're upset.
just to help with a couple of your fears, i'm gonna try and spin some stuff round here:
Being alone (I have a couple friends in my city but not many as this isn't where I'm from take this as an opportunity to get out there and make new friends, and join groups (take up a hobby/do some charity work!), and build a social circle. if all else fails and you hate living alone in the city, you can always go home/somewhere safer/more familiar for a while, and give living alone another shot when you feel stronger too- its not a failure to do this, its self preservation to choose to be somewhere you feel safe.
Getting sick and having no one that will be there for me see above- you can do this! an abusive partner might not be much use if you're sick, maybe more of a burden, even... if he can't walk a puppy when you're ill now without having a meltdown, he probably won't handle caring for you in a more substantial way well either, and'll last 5 minutes in a crisis before he's moaning, having a temper tantrum, or looking for the door.(sorry to be blunt!)
Having opened up quite a lot to a person and having it be for nothing nothing is ever for nothing... i bet you've learned and experienced and grown a lot as a person while you've been with this guy (good and bad) but that doesn't mean you have to continue to be with him to continue to learn and grow.
Seeing a lot of good attributes in him (that I haven't mentioned, because I'm looking for help to deal with the bad, but can and will mention the good if anyone wants to know) if he gets help, that good'll still be there, and he'll be healthy to be with as a partner, if you both still want to give it another shot. but right now, the good doesn't outweigh the bad, and it sounds like your relationship is not a healthy place to be for either of you currently.
He is the first person I've been with that I've started to work on my sexual triggers with, which requires quite a bit of trust. you've learned to trust someone with your personal stuff, thats great! i know that when its time, you'll also find that trust and intimacy with someone who doesn't treat you with such disrespect, or if you choose to rebuild a relationship with your current partner down the line, that you'll be able to rekindle it.
good luck, whatever you choose to do- and please don't go it alone, keep seeking out help, and taking it, as long as you need it!