I am so tired now, even ifthough it is 8 p.m,PM. I've taken a shower and I wanna go to bed.

I am so tired now, even ifthough it is only 8 p.m,. I've taken a shower and wannat to go to bed.

This is a run-on sentence. Another way you could fix it is by putting "even though it is only 8 p.m. onto the second sentence:
"I am so tired now. Even though it is only 8 p.m., I've taken a shower and want to go to bed." Which way communicates what you want to say? Do you want to say that you are surprisingly tired for bed for 8 p.m.? Or do you want to say that you've already prepared for bed by taking a shower, which you normally don't do by 8 p.m.?

Also, "wanna" is acceptable in spoken English and with text messaging or email, but with most written English you should say "want to"

I am so tired now, even ifthough it is 8 p.m, I've taken a shower and wanna go to bed.