I have checked your account and your forms are disabled because Upload space on your account is 242.26 MB and for free users available Upload space is 100 MB. I have checked your account and I saw that there are no submissions on your forms. However when I checked your Trash folder I noticed that some deleted forms have submissions. Please delete submissions from the forms that are inside of your Trash folder.
Also you do not need to delete forms to clear your upload space only submissions.
Hope this will help. Let us know if you need further assistance.