With the facts as you described them, you will not be able to expunge the earlier two retail thefts. It is suggested that you hire an experienced criminal defense attorney. I gave seen lawyers work miracles and convince the prosecutor to resolve a felony retail theft to a summary. I'm not saying that will happen here, but under the circumstances it is worth a try.
I agree with what has been said by Mr. Keller and have the following to add. You should not place more of the facts of your situation in a public forum like this. Securing qualified counsel needs to by your single goal at this point. I would be happy to discuss this with you privately; feel free to contact me at your convenience.
You should speak with an experienced criminal defense attorney as soon as possible. The court will not expunge the summary offenses with the felony charge hanging out there. However, your primary concern should be defending yourself against the felony, as this charge can carry significant jail time and other penalties.