What to do with slow website upload?

Hi.

I think my website are uploading a bit slow. When I enter the site in Chrome and Explore it slow when uploading. When I log in to my site it is also very slow.

I have 18 active plugins. Is that alot or should it run ok with this number of plugins?

I have resized some of my images to website size. Maybe this helps.

Can you help me with this? I have deleted all installed plugins that I didn't used. Maybe you have some tricks for this.

Looking forward to hear from you.

Best, Tim