Doubts regarding tahaarat

I was performing ghusl after masturbation. I was taking baths and mumbling songs. Suddenly the shampoo bottle fell on the shower and it broke. So I wore my clothes and came out then my dad called the plumber after scolding the hell out of me. But I have some concerns. I took the bath while mumbling songs and didn't perform wudu yet. Now I feel like I didn't take the bath properly and like negative thoughts are coming to me that not all hairs of my body were wet. And stuff like that. This happens to me when I am praying and often repeat aayats and wudu because of these waswasas. So now please tell me what to do. Now the tap will be fixed in 1 day. So now I think I should perform wudu and start praying then those thoughts come to me and make me feel that no I shouldn't perform wudu now because I didn't take a bath properly. And the way I do ghusl is that first I wash off all the impurities then wet my body and hair. But I am really confused that how should I make sure that my back is wet too. I can't look at my back. So because of this confusion I waste a lot of water. So please tell me what to do.