Delete a block of sentences where the start and end of block is clearly defined

As you said the block are limited between # and $. We can treat the text as numerical sequences between those signs. Use finditer to point the blocks limits.

    import re

    starts =[]
    starts = [s.start() for s in re.finditer('###',text)]
    # [0, 105, 349]          

    ends = []          
    ends   = [e.end() for e in re.finditer(re.escape('$$$'),text)] #special char $
    # [104, 348, 558]

    blocks = []
    blocks = list(starts+ends)
    blocks.sort()

    #sequence of blocks
    nBlocks = [blocks[i:i+2] for i in range(0, len(blocks), 2)]
    #[[0, 104], [105, 348], [349, 558]]


    #find where the input text belongs       
    for i in text:       
        find   = '22 feb 2017 21 april'
        where  = text.index(find)
    # 10  

    #removing block elements    
    for n in range(len(nBlocks)):
        if where in range(nBlocks[n][0],nBlocks[n][1]): 
            for x in range(nBlocks[n][0],nBlocks[n][1]+1):
                             #text starts          #text ends
                 cleanText = text[0:nBlocks[n][0]]+text[nBlocks[n][1]+1::]


    print(cleanText)

    ###
    risk true stories people never thought they d dare share
    risk true stories people never
    true stories people never thought
    stories people never thought they
    people never thought they d
    never thought they d dare
    thought they d dare share
    $$$
    ###
    everyone hanging out without me mindy kaling non fiction
    everyone hanging out without me
    hanging out without me mindy
    out without me mindy kaling
    without me mindy kaling non
    me mindy kaling non fiction
    $$$