Thi, you misunderstood the prompt requirements. You were being asked to discuss both points of view from a general perspective / reasoning before you presented a discussion of your personal opinion. This is evidenced by the prompt instruction indicating:
Discuss both views and give your own opinion.
From the way you presented your thesis statement, it became evident that you were discussing only your point of view rather than the two point of view plus personal opinion discussion because you indicated an opinion immediately that stated:
From my personal perspective,
The proper thesis statement for this essay is:In this essay, I shall examine both discussion points as supported by each group prior to the presentation of my personal opinion.
You have to remember that the opening statement is only a representation of your understanding of the original discussion. It should never contain a personal opinion or begin a discussion of the presentation as there is no time to further develop your explanation in the paragraph based on the 5 sentence maximum presentation per paragraph. The general discussion should only be done in the 3 body paragraph. Don't forget to show ownership of the discussion in this type of essay discussion as well. Ownership terms need to indicate what opinion is being discussed and from whose point of view. So you could say:
"There are a group pf parents who believe that... because...
The dissenting point of view indicates...
My point of view is that..."
By showing ownership, you will be able to better highlight the clarity and coherence of your discussion. Don't forget to use transition sentences at the end of each paragraph to help introduce the next topic for discussion to the reader. It makes for a smoother read and allows for a higher GRA score.
Try to avoid presenting long sentences that separates discussions using a comma. Short sentences that presents connected discussions have a better chance of improving your overall score. Present at least 3 sentences each time and you will have a better scoring consideration for sure.