How do I use a variable within another variable in an ORACLE SQL Loop?

I am attempting to use a loop in my Oracle SQL code that will change the name of the schema slightly each time the loop is run. I have tried the SQL code below, creating a NUMBER variable that counts up from 1 to 3 and then concatenating it with the schema name, but I keep receiving a long error message. The schema name should be 'x_rm_mt1_d' the first loop, 'x_rm_mt2_d' the second loop, and 'x_rm_mt3_d' on the final loop. The select statement in the code below is just a small example of what I am trying to do, I didn't think it would be pertinent to include the entire query that I am looking to use the variable for.

    DECLARE
      l_counter NUMBER := 0;
    BEGIN
      LOOP
        l_counter := l_counter + 1;
        IF l_counter > 3 THEN
          EXIT;
        END IF;
      DEFINE StrSchema = 'x_rm_mt' || l_counter || '_d'


    WITH aed AS (



SELECT DISTINCT SSN , STATE FROM (
--Effective Date During Quarter
    SELECT *
    FROM
    (SELECT * FROM ADDRESS_EFF_DATE 
    WHERE STATE = 'VT'
    AND EFF_DATE >= '01-JAN-20'
    AND EFF_DATE < '01-APR-20'
    AND ADDRESS_KEY = '0'
    
    )aed
    WHERE aed.EFF_DATE = (
            SELECT MAX(aed2.EFF_DATE)
                FROM ADDRESS_EFF_DATE aed2
            WHERE aed2.CONTROL_ID = aed.CONTROL_ID
            AND aed2.SSN = aed.SSN)

--Effective Date Prior to Quarter
    UNION

    SELECT *
    FROM
    (SELECT *
    FROM Strschema.ADDRESS_EFF_DATE
    WHERE STATE = 'VT'
    AND EFF_DATE < '01-JAN-20'
    AND ADDRESS_KEY = '0') aed
    
    WHERE aed.EFF_DATE = (
        SELECT MAX(aed1.EFF_DATE) 
        FROM Strschema.ADDRESS_EFF_DATE aed1 
        WHERE aed.ssn=aed1.ssn 
        AND aed.EFF_DATE < '01-JAN-20' 
        AND aed1.EFF_DATE < '01-JAN-20')) )        

,

--Select all records from Employee Eff Date Where Latest Hire Date is before 4/1/20
--AND Term Date is Null or Term Date is Greater than 1/1/20 eed AS (
       SELECT *
    FROM
    (SELECT *
        FROM Strschema.EMPLOYEE_EFF_DATE eed
        WHERE eed.CONTROL_ID = 'SMLMKT'
        AND eed.EFF_DATE = (
            SELECT MAX(eed1.EFF_DATE) 
            FROM Strschema.EMPLOYEE_EFF_DATE eed1
            WHERE eed.SSN = eed1.SSN 
            AND eed1.CONTROL_ID = 'SMLMKT') 
     ) eed3      
    WHERE eed3.LATEST_HIRE_DATE <= '04-APR-20'
    AND (eed3.LAST_TERM_DATE > '01-JAN-20'
    OR eed3.LAST_TERM_DATE is NULL) ) ,
     ebe AS (   
    SELECT *
    FROM Strschema.emp_ben_elects ebe
    WHERE ebe.control_id = 'SMLMKT'
    AND ebe.BENEFIT_ID = 'MEDICAL' 
    
    AND ebe.life_event_date = (
        SELECT MAX(x.life_event_date) 
        FROM Strschema.employee_life_events x
        WHERE x.ssn = ebe.ssn
        AND x.control_id = 'SMLMKT' 
        AND ebe.p_company_id_i = x.p_company_id_i 
        AND x.life_event_status = 'C')
    
    AND ebe.le_seq_no = (
        SELECT MAX(x.le_seq_no) 
        FROM Strschema.employee_life_events x 
        WHERE x.ssn = ebe.ssn
        AND x.control_id = 'SMLMKT' 
        AND ebe.p_company_id_i = x.p_company_id_i 
        AND x.life_event_status = 'C'
        AND ebe.life_event_date = x.life_event_date)
    )
    
    

SELECT  cmp.NAME as "Client Name" , cssn.REAL_SSN as "Employee SSN"
--, aed.SSN as "FAKE SSN REMOVE" , eed.LAST_NAME as "Last Name" , eed.FIRST_NAME as "First Name" , aed.STATE as "Resident State" , eed.LATEST_HIRE_DATE as "Hire Date" , pi.DESCR1 as "Plan Name" , ebe.OPTION_ID as "Tier" , ebe.BENEFIT_EFF_DATE as "Coverage Start Date" , eed.LAST_TERM_DATE as "Coverage End Date"
--, eed.LAST_TERM_DATE

FROM eed  INNER JOIN aed ON eed.SSN = aed.SSN

LEFT JOIN ebe ON eed.SSN = ebe.SSN

JOIN Strschema.COMP_SSN cssn ON eed.SSN = cssn.SSN

LEFT JOIN Strschema.PLAN_INFO pi ON ebe.PLAN_ID = pi.PLAN_ID AND ebe.BENEFIT_ID = pi.BENEFIT_ID 

JOIN Strschema.COMPANY cmp ON eed.CURRENT_CO = cmp.COMPANY_ID      

      END LOOP;
          END;