Hi Debbie, I agree with many above that it's well worth having another editorial assessment done by a professional, get really detailed feedback and action that, then try to submit again. It's not cheap doing this (paying for the assessment) but it may be money well spent - in any event you will end up with a better book as a result, which means if you do go down the self pub route you are making the best representation of yourself as a writer.
If, after all, you decide to self pub then do consider the Amazon route. I did so with my first novel and it really isn't that difficult - they give lots of tutorials on how to do it and it's easy to work out (if a little trial and error to begin with). You can preview every format before you publish. It is really important to get a great cover created by a professional graphics artist - if they work with books they will be able to understand all of the sizing and formatting guidelines given by Amazon and will produce it in a format that you just simply upload, so it's worth choosing someone with experience in print design (as opposed to just web design).
Apart from the costs of the editorial assessment and the cover design, everything else on Amazon is totally free to use. You don't pay any print costs as they print to order (meaning they will dictate the cover price for the paperback/hardback depending on the book's length and cover design).
Like a couple of people have said, publishing it is the easy bit! Drumming up readers is as sole-destroying as trying to find an agent! And then you have to develop a skin thick enough to take the less kind review comments (which all books get) - which are on public view - but hopefully you'll get a good amount of positive reviews too! In my experience, though, getting people to read it is tough, getting them to review or rate it is even tougher. My book has been live for over 2 years, it's had just shy of 800 Kindle downloads and has 55 ratings, including 19 reviews. And I have put a lot of effort into social media, website, free promos, Amazon ads, etc...
The marketing is a full time job, which I sadly don't have time for. But I guess you could pay someone to do that for you - I'll imagine it doesn't come cheap. The best thing about self-pub is the satisfaction of seeing your work in print, which is still the best part for me. I wrote it for the joy of it and published it for the same reason.
But once it's out there, you can't help but get hooked on watching your numbers....