Often, posting the whole work isn't necessary; take lessons learned from one part and apply it to the whole. Say, if you're prone to excessive adverbs, or your MC comes across as spineless and annoying (when you were going for a witty rogue), that's something that shouldn't take the whole manuscript to get across. That's another reason why you might want to slow down, especially if you do plan on posting the whole thing - if you rush to post, and are repeating the same issues over and over again because you haven't taken the time to think through the advice given and apply it to the whole story, people will likely get frustrated and stop replying.
As others have said, you might consider a dedicated partner or beta - which you can search for right in this forum, under the
Beta Readers, Mentors, and Writing Buddies section. SYW's a good place to start, but it's not ultimately a substitute for a detailed manuscript beta/critique.