Yep, it's a vicious cycle..... I didn't even realize how much alcohol affected me until I'd been sober for a good number of days. Everything was so hard when I was drinking and I thought it was just me, when in fact, it was the alcohol.
It's hard not to feel the guilt/shame at first, but it really does get better each day you stay sober. Remember, all we have is today (this minute, really) and all we can do is make better choices moving forward.
You've already taken a huge step, so give yourself some credit for that!