Icky stout- green or infected?

Newbie question
I realize this topic has been addressed ad nauseum, but I haven't found an answer that directly pertains to my case.
My first brew was a Midwest irish stout kit. I followed the 1-2-3 schedule. The first bottle I tried tasted a lot like guiness, but had a very bitter finish. I assume it would classified as astringent. The best comparison I can think of is that it tasted like coffee that had burned in the bottom of the pot. I figured this would either be because it was green, or that it was because I had boiled the grains instead of steeping them (I'm an idiot).
However, after trying a bottle each week for the last 4 weeks, the off flavor has been getting worse, significantly worse. It seems that whatever the flavor is won't be getting better with time. I am perfectly content to give it more time, but I am starting to wonder if the beer is infected. Also, I didn't realize until later that I had only cleaned the equipment (including primary and secondary) with the cleaner that came with the midwest kit (I wrongly thought that it was a sanitizer).
Does this sound more like an infection, or something that may get better with time?
By the way, I corrected all of my initial mistakes on my second brew (MW irish red) and it tastes great.

The boil instead of steeping probably was your problem here. I imagine it is a lot like chewing on peanut shells. At least you recognized your mistakes. I have many scars that prove I never learned anything the easy way.

Just had another bottle. Compared to last week, the taste definitely continues to worsen. One month ago it tasted a lot like guiness, but with a bad aftertaste. Now the guiness taste is gone, and all I taste is the bad aftertaste. Would this happen if it was just the tannins?

put it in the back of the closet, whats the worse that could happen?try again in 1 month, 2 months and so forth. dumping it now frees up bottles but why not wait it out for awhile?

I agree with Crazy, boiling the grains is the likely culprit. You will usually notice an infection before you bottle.

Also, it seems the consensus is that the 1-2-3 method is not the best. I usually primary for 3-4 weeks and then bottle. This extra primary time will help to clean up off-flavors, such as those you are experiencing.