Please talk to your doctor about those concerns though here is a site with general information about inhalant use and its effects:
http://www.inhalants.org/about.htm and can click on one of the links.
You're very fortunate that you do feel okay. Not everyone is so lucky. My friend has a Traumatic Brain Injury (TBI) from huffing at the age of 12, now in her 30s.
If you're not in any type of program such as Alcoholics Anonymous (and/or substance abuse counseling), please consider attending those 12-step meetings such as AA to help support your sobriety (staying sober and engaging in positive behaviors). Just fyi that one may attend an "open" meeting if doesn't have a drinking problem.
To search for free 12-step AA meetings: http://www.aa.org
For counseling and treatment programs for those with addiction(s), and some may have state and/or county funding available for counseling: http://findtreatment.samhsa.gov/ and can click one's state of residence on the map and continue with the search.