Unfortunately, I bought $100 worth of XRP a few days ago @ $0.36 and it is not worth about $0.26!! This is the problem with most centralized coins. A wrong decision by a person or some organization will ruin the investors' efforts.
What do you recommend me to do now? Do you think Ripple will rise sooner or later?
Should I hold my coins or is it better to sell them as soon as possible to prevent further damage to my investment?
What about converting it to other coins to compensate for losses? (This is hardly possible now because all coins are expensive now)
We can't recommend you anything. You have to do your research before or after you invested. I had sometimes invested $1000 in Ripple and I couldn't hold for more than one hour.
Right now there is a wait and see stance from the remaining investors. If Coinbase goes and delists it, then it will be over. Only inside traders will know, another terrible result of centralization.