I'm sure you'll be happy to come back.
Restrictions are very low here now. Facemasks are required indoors, on public transport, in medical facilities and recommended in crowded places such as markets etc. Also for entering restaurants but can be removed once seated.
You will need a vaccination certificate. This needs to show your vaccination status that you had both vaccines (1 of Janssen) more than 14 days ago but no more than 270 days (9 months) ago. If it is longer than 9 months then you need to show the booster vaccine but there is no time limit on that one.
You will also need the medical check, commonly called the Passenger Locator Form, to enter.
These restrictions are being looked at and will probably be scrapped after Easter once they see how the virus is progressing. As a heads up, cases in Spain were around 1,500 per 100,000 just a few weeks ago but have dropped to around 400 per 100,000 now. Some regions, like Valencia and Andalusia, even lower at just over 300. The facemask rule will be dropped once it gets to 50 per 100,000.
No covid passports required to enter establishments except for residential homes.
To be honest, the facemask bit is no problem as you aren't really in shops or supermarkets for that length of time. Lots of people still wear them outdoors in towns although it's no longer law, just a recommendation. Seems a bit surreal to go into a pub and have to have the mask on when ordering in the bar or going to the loo when everyone else inside at tables aren't wearing them. Still, no real problem. The social distance of 1.5m is still in place but doesn't seem to be being adhered to. Even seen people back to the hugging and kissing as a greeting again.
Not been at airports myself but people are saying it's virtually back to normal and very quick. Just the bit about having your passport and paperwork check causing holdups but it seems to be fairly quick. Getting through security on the way out seems to be the only delay and can take quite some time, especially as people are trying to find their paperwork on the mobile phones. Couple across the road from us said they opened two lines, one for people with the paperwork printed out and going through quickly and the other for those with the paperwork on their phones trying to find it.
Enjoy, Storm Celia has hit us here on the Costa Blanca at the moment and the skies are bright orange and red with all the Saharan dust and fairly high winds. Not expected to rain a lot until Thursday when I suppose it will change to red mud and have to get the pressure washer out again. Temperatures are not affected, though, and it's quite warm in the daytime and doesn't get really cold at nights (although a coat will be required once the sun goes down).
All the above will have disappeared when you come over in May and the sun will shine on the righteous and non-righteous just the same.