Hi Tristeve and welcome to OCF.
I have not had the same treatment as you but I know from being on the forums here that what you are feeling is not uncommon. I'm sure other people will chime in about their experience with the PEG and how they used it. One thing I have learned is that it is important to continue to swallow and use those muscles. Do you take the Ensure in the PEG?
In reagrds to the anti-depressants...a lot of people take them. Cancer has a way of causing depression and anxiety. I take Lexapro. If you started taking them 2 weeks ago you're probably not feeling the full effects yet, they can take up to 6 weeks.
You did have a lot of treatment so give yourself time. You have found a wonderful group of people who are sure to help you and make you feel better. Knowing that you are not the only one makes a big difference.