Been very forgetful lately?

I'm very concerned! I've been very forgetful lately....I'll forget very simple things that are pretty simple to remember. I don't drink much water and idk if that can be a contributing factor. I don't have a vitamin deficiency I know that much. For example right before I left work I thought in my head don't forget to grab your ring and don't forget to clock out. I set the alarm and go outside and what did I realize I forgot? My ring and to clock out! Or I'll be thinking something to tell my husband and then right when I start to tell him it totally slips out of my mind! I've also been getting tongue tied a lot lately...idk what my problem is but it's freaking me out and kinda making me think I have a brain tumor or something. I also just finished my period so idk if it could be that. Please help me out. I'm 21 years old and not overweight and I'm relatively healthy...