I believe you have some solid material here, it will just need organised into a strong speech.
I hope some of the tips below can help. I would say to start with that I believe in making positive, inclusive graduation speeches.
If you decide to make a positive, all inclusive graduation speech, written in simple language then you should have good material. The whole audience are there to hear you so they should be included. I hope you can present your thoughts in a way that will positively impact everyone.
Opening
Consider starting with the easiest opening which is formal. For example Principal, Honored Guests, Teaching Staff, Fellow Students and Families.
Congratulations Class of 2008.
This should help bring people on to your side right from the start.
Middle
This is where your theme and material need to bind together to give you the flowing graduation speech you deserve.
Consider right away thanking everyone. There are all those who have helped, professors, family, fellow students and mentors. There are also those who have helped generally with all your class.
Consider the flow of the speech. Start with reflecting back on the past 4 years. You may have lots of material, great stories, events and your personal notes on how you faced challenges.
Then on to celebrating the present and taking your theme forward to the future.
I don’t know your exact story but I expect you will have some great material.
For example: Arriving here at College I was very much at a disadvantage. I used that disadvantage to my advantage.
Overcoming these difficulties has been the making of me.
Through sheer hard work and perseverance I worked my way into college life and eventually my grades improved to the extent I have graduated today.
Looking back I take great pride in knowing all of you and have really come to feel close to my class.
I learned too the impact on my life of giving to others. Knowing what it is like to have disadvantage in your life I realised I could really help others. I have loved it and I hope they all got something out of it.
Perhaps you are able to expand on your own hard work, how you tackled adversity, how you contributed to others, how you joined in. Also how much you enjoyed college and what it has given you for the future.
Perhaps you can set out your lessons learned and how you will use them.
I hope you can see some powerful messages in your material.
Back to the present, congratulate everyone again and enjoy the celebration.
End
Looking to the future wish everyone all the best.
If you have lessons learned what will you be doing with them in the future.