Hi, Unreplaced missing teeth leads to all the problem you have mentioned and it will keep on worsening leading to more spacing between teeth, gum problems and even more decayed teeth. Pls go and see a dentist who will do a thorough examination and explain to you the treatment required. An ideal treatment would be to do a orthodontic i.e braces treatment followed by replacement of your missing teeth. Hope that answers your query. Thank you.

Go for replacement of missing teeth , either fixed partial dentures or implants.

Whatever done is done. You had to get 3 of your molars to be taken out. Pls get your self treated for all teeth disorders first so that no more teeth would require to be extracted. Also, keep your teeth checked regularly at a dental clinic twice a year atleast. The treatment of choice for you would be orthodontic treatment I.e braces. Get your teeth aligned properly and then replace your teeth either as a bridge or implants