If you are going in for years, then sell what you can for the money, as when you get out it will be old anyway and the money will do you more good in jail. You will need that money to last you your entire time there, and you will really regret not having it too, it you are broke. Spend it slowly in there, and try not to let anyone see how much you have. Spend it slowly if you have it, so it lasts and they do not think you are a rich target, and do not let them know you have any money or where you get it from. Many will try to force you to get anyone sending money to you to also be sent to them.
Poverty breeds desperation.
If you can, have a friend that you can trust with you life send you your money a little at a time, instead of having it all at once. Because some prisoners can get access to the records one way or another, and if they see you have a lot, they will force you to give it to them. If you do not have family then maybe you have friends. At least I hope you do. And there ARE groups out there that are specifically for people like you if that is the case, in jail with no family, and most are religious, but they do not insist you follow their religion to get help.