Help with 22 night itinerary please.

It's great that you're giving yourselves 3-night stays. Are you considering going to the Aran Islands?

In general it looks like a well paced itinerary.
Just a few thoughts: I think your back to back stays in Galway and Westport will be redundant if your goal is to explore the beautiful Connemara region. Staying in one or the other for 3 or 4 nights would give you plenty of time to explore, to include a day trip out to the Aran Islands as previously suggested. Our favorite little town is Clifden - close to the very pretty Sky Road scenic drive and central for explorations around Connemara. Might be a good alternative, and a little more rural, than staying in either Galway or Westport.
Would be a shame to come all the way to Ireland and miss the charms of the Ring of Kerry, especially the northern half that includes the Skellig Ring, the Kerry Cliffs and the Gap of Dunloe - possibly the prettiest little glen in Ireland. Rather than staying in Dingle town, you might consider staying somewhere nearby between the villages of Castlemaine and Glenbeigh - and thus be centrally located for short drives to all of the nearby attractions including the National Park over in Killarney which is worth a visit if only for the day.
Portrush would be a good base for exploring Derry, parts of beautiful Donegal, and the Causeway Coast. If your heritage traces to Ulster I'd suggest a stop at the Ulster-American Folk Park near Omagh - does a great job of explaining the history of the out-migrations of the early 1700's.
On your way down to Belfast I recommend going by way of the coastal road thru the Glens of Antrim - another one of the most beautiful scenic drives in Ireland. Lots of old castles to explore along the way.

I like that you are taking a slower pace and not doing a bunch of one night stands, but some paces don’t need three nights. Kinsale is probably one you could take a night from as it is quite small. You may want to consider a stop in Kilkenny for a night or two. The Killarney area has a lot to see, also, and I would highly recommend doing a jaunting car through the Gap of Dunloe.

Thank you all so much for taking the time to reply. I'm sure no matter where we stop it will be fantastic but it's always good to get other peoples advice.
We'd like to do a day trip to the Aran Islands. Which one would you suggest we see?
We will probably stay in Clifden now rather than Westport. It sounds like a beautiful spot to base ourselves for exploring the Connemara area.
Thanks again!!!

You're right - no matter how you choose to organize your trip it will be great. It's Ireland after all.
The easiest option from Clifden is to drive over to the ferry landing at Rossaveal - about an hour away. There's a free parking lot on site. Weather shouldn't be an issue that time of year, but just in case you might want to check the forecast a day or two in advance before committing to a particular day. Although the ferries themselves are sizeable craft that can handle the sometimes rough crossing without too much drama, you probably wouldn't want to be on the boat in rough sea states. Plus, touring the island of Inishmore is much more pleasant on a sunny day.
The ferry typically doesn't sell out so you do have the luxury of waiting until the last minute to book.

We did a very similar trip last summer. Except we did a few 1 nights stays so we could get from point A to point B without rushing. We stayed 3 nights Dublin, 1 night Kilkenny, 1 night Waterford (added so we had time to visit the place where my father grew up), 1 night Kinsale, 1 night Kenmare( ½ Ring of Kerry next day), 1 night Portmagee (Skellig Michael next day), 3 nights Dingle, 2 nights Doolin, 1 night Aran islands, 1 night Westport, 3 nights Ardara, Donegal, 2 nights Portrush, 1 night 1 Bangor, and 3 nights Howth. We had certain places along the way that we wanted to revisit, combined with places we wanted my daughter to get a chance to see.

If we did it again we would 3 nights Dublin (Buswells Hotel), 1 night Kilkenny, 1 night Kinsale (one of my favorites), 1 night Kenmare (perfect starting point for ring of Kerry), 3 nights Dingle (Greenmount B&B), 1 night Aran Islands, 3 nights Westport (heading back there for 1 week this summer we loved it so much), 3 nights Ardara, Donegal (visit Maghera Caves & Beach and Nancy's bar), 2/3 nights Portrush (Blackrock B&B), and Belfast then on to Dublin for return flight home. I would highly recommend creating your list of places that are must see. Any must see places that are also popular bus tour stops try to plan on visiting these either first thing in the morning or in the evening to avoid the crowds because some of these locations get really, really, crowded.

I know you said you would prefer 3 nights at one place and I completely agree with you but take a look at the Kilkenny, Kinsale, and Kenmare stops and map out where you would like to visit. It's possible that this could work for you. But if I had to pick one for a 3 night stay it would be Kinsale. It's one of my favorite towns in Ireland.