Depression .

I don’t know what’s wrong with me, I’m not depressed all the time but when it comes it stays for two weeks, my personal hygiene will be terrible, I won’t go out, I won’t get out of bed, il sleep in late, barely eat, and take myself away from society then the other half is I will be extremely happy, I will bath twice a day ( sounds stupid but a lot for someone whose to depressed to even brush their hair) il make plans, be positive be excited . This has been happening for nearly a year, And it swjtches between being really happy or really depressed and I hate it. I am going to go to the doctors soon but don’t want to seem stupid :( thanks in advance x

Can I also add I’m only 17 and have heard it’s not very common for a younger person to have bipolar