After months of negotiations the two clubs reached an agreement on Tuesday in the build-up to Spanish's side's Uefa Super Cup clash with Real Madrid in Cardiff.
"I am in a strange situation because I'm leaving the club of my life," he told ABC de Sevilla . "There are a lot of mixed feelings. I wish the best for Sevilla. I am a Sevillista and I want them to keep growing.
"What I experienced on the pitch with the fans (on Tuesday) will stay with my forever.
"I couldn't help but cry because I wasn't expecting it. First the goodbye with my team-mates, then with the fans... it's all very hard."
Liverpool had been frustrated in their attempts to agree a fee with the Andalusians as far back as June, but renewed talks at the start of August and will shortly confirm their eighth summer signing.
But while Moreno is sad to leave the Ramon Sanchez Pizjuan, he was always hoping a deal would go through.
"Sevilla have understood that Liverpool's offer is very good, and I'm going," he added.
"I was always waiting for the two teams to reach an agreement. I never got involved in that. Liverpool are a great club and of course I go there extremely motivated. I hope that things go well for me."
Sevilla coach Unai Emery admitted after the defeat to Madrid that Moreno's departure had been a long time coming, telling the press: "The offer has been on the table for a month-and-a-half to two months. I saw him leaving the club earlier than I saw right now but it's unfolded today [Tuesday].
"We knew they were following him in England, the teams who were interested and that the meetings were advancing. We were prepared to lose Alberto.
"Unfortunately, we were counting on him being here with us today but Fernando Navarro put in a great performance. We're looking for another good player to join us, who can help complete our objectives."