everything sounded great until the upgrade

You don’t give much info. 
 

new electronics can take several weeks worth of continuous music playing to break in. Until break in completes sound can be thin compressed and lacking in warmth and bass. 
 

if you have passed the point of break it you may have a bad match. 

I'd agree with a lot of the comments here. Listen to it casually for several weeks to let the amp settle in and for you to get use to the sound. Then you can begin to decide on what needs improvement.

A good high quality DAC would solve your harsh CD sound. You could use your existing CD player as a transport if it has some kind of digital out (optical, coax, etc.)

Before I knew about DACs (circa last year), I thought that was just how all digital sources sounded - harsh and bright. Early this year, I bought a Chord Qutest DAC, and now the vinyl upgrades have taken a backseat to the digital upgrades.

Don't forgo high quality cables if you're going this route - not to trigger, cable deniers, but for me it was the difference between really good and transformative.

I hadn't plan to spend as much as I did, but after the fact I found it to be money well spent.

You don't say what amp. you have so it is difficult to comment. Have you somehow changed a "gain" setting somewhere in your system that could be affecting how aggressive and unpleasant it now sounds? 

It appears you liked the sound of your previous amp.  Perhaps sell the amp and replace your CD player with a really nice streamer.  I have an OPPO 105 and no longer use it.  Who wants to get up to change a CD?  I like also my huge library and easy access using Tidal.

Let the new amp break in, sometimes it takes weeks. Never turn it off.

Try an outboard DAC with a tube output buffer.

My Amp doesn't even have an on/off, switch,same said for my pre-amp and Phono amp.

Turing your gear off and on just kills it's life span and doesn't help the sound. I work in broadcast with gear costing  thousands and thousands and thousands of dollars and it all stays on till it fails.

Give it time, you could end up all right.

There are also a ton of inexpensive tweaks that can make a huge difference too. 

Just putting 4 McCormack Tip Toes under my old Conrad Johnson turned  a very good amp into a sumptuous sounding piece of gear.

HiFI tuning / Synergistic fuse to replace the main power fuse, better power cord and AC outlet ( even just Green Dot hospital grade AC cord/outlet) etc are all reasonably priced add on's that can make a big difference.

Don't chuck the amp out yet.

Hope some of these things will help!