Although desire for sex is healthy and normal, and masturbation even once or twice a day is fine, four or five times a day is a bit excessive.
It sounds like you became hypersexual at some stage. What changed a year ago? Although the cause for this cannot always be determined, the following is thought to contribute to it:
Bipolar disorder
OCD
Mind altering medicines and diseases
Drugs
I suggest you see your doctor and make sure everything is ok. This may be just normal for you, but it is better to make sure it is not a sign of something else.
Please stay safe, always!