How can one get rid of masturbation and watching pornography to return to faith, and is the doer of that considered a hypocrite because he forbids evil while committing it secretly, and must he abandon the work of da'wah (proselytization)?

You are engaged in a tremendous good by performing da'wah (inviting to Islam) and adhering to the religion, so do not let Satan divert you from that. The cure for your masturbation and looking at forbidden things is to distract your mind from them and to distance yourself from everything that incites you, along with supplicating to Allah to avert evil and indecency from you. You have an excellent example in Yusuf (Joseph). By abandoning provocations and making supplication, you will triumph over yourself. You are not among the hypocrites, because they do not feel guilt, whereas your soul admonishes and blames you; otherwise, you would not have written to us. Seek help from Allah and ask Him to avert these ugly acts from you, and do not abandon the good you are doing.