What you written absolute correct. only i introduced one more query for that output. may be it will help you.
with temp as (
SELECT FYear.Session, case when FeeHead.FeeHead like '%(AC)%' then replace(FeeHead.FeeHead,FeeHead.FeeHead,'Annual Charges') else FeeHead.FeeHead end as FeeHead,
SUM(FeeItem.Amount) AS Total
FROM FeeItem
INNER JOIN FYear ON FYear.SessionID = FeeTransItem.SessionID
INNER JOIN FeeHead ON FeeItem.FeeheadID = FeeHead.FeeHeadID Where(FeeItem.FeeItemID = 18192)
GROUP BY FYear.Tag ,FeeHead,FeeHead.Serial
)
select Session,FeeHead, SUM(Total) AS Total from temp
GROUP BY FeeHead