The Dutchman, who has been recently reinstated at Ismali, saw the coastal team lose their first competitive game under his guidance on Sunday.
Wotte's men controlled most of the CAF Champions League match and carved out many scoring chances but eventually slumped to an embarrassing defeat.
"I'm really depressed about the result and still cannot believe we lost," Wotte told the post-match press conference.
"We created many opportunities but there was no luck. Any team that squander that much of chances should expect to concede goals.
"But we cannot compete in the African Champions League only with two strikers at our disposal. We need to bolster the frontline."
Ahmed Ali and Mohamed Mohsen formed Ismaili's strike partnership throughout the 90 minutes of the match.
Abd-Rabou's Absence
Wotte believes that Hosni Abd-Rabou's absence did not negatively affect Ismaili during the match.
"Abd-Rabou is an important figure but we weren't influenced by his unavailability. Our problem is the attack," he added.
Egypt midfielder Abd-Rabou missed the game through a cruciate ligament tear.
He is set to undergo surgery in the immediate future.
Crucial Win
Ismaili are now languishing at the bottom of the Champions League Group B with no points.
Wotte said his team must beat Ahli in their upcoming match in Cairo to stand any chance of qualifying for the semi-finals.
"This is crucial. We have to beat Ahli in the next game. Losing one more time we leave us in an unenviable situation," he added.
"We still have three weeks, during which Ismaili's board have to bring in new strikers."
Ahli and Heartland have one point each after playing out a 1-1 draw.