Can I apply for F-1 with an approved I-526?

Your approved I-526 cannot necessarily be used to obtain F-1. However, you can and should try to obtain F-1 to pursue your graduate degree by fulfilling all admission requirements.

I would not try to get a new visa but if you stay here and just get a new I-20 should be OK.

If you are in valid F-1 status, you should be able to get a new I-20 from your school and thus extend your status, even if you have an approved EB-5 case.

Your I-526 petition is an immigrant petition, expressing your intention to permanently reside in the United States. F-1 visa status is for nonimmigrants only. That said, as long as your timely file your application to continue (OPT to F-1 student) full-time studies in the United States, you are eligible for consideration by USCIS to continue in this nonimmigrant status. You could have filed for adjustment of status in March because the dates for filing (12/15/2015) on the March 2020 Visa Bulletin were allowed by USCIS. In April, however, USCIS required the final action date of 05/15/2015 to be used. Once your priority date becomes current (or dates for filing are once again allowed) in a future Visa Bulletin, you can apply for adjustment of status (if you are in valid nonimmigrant status at that time).

It may be possible to continue studying by getting a new I-20, but as for getting a new visa at the consulate, they may be a little less cool with the I-526 being approved.

Certainly, you can apply. You will have to prove that you do not intend to immigrate to the U.S. That could be difficult to prove.