Within the last year I have started suffering from premature ejaculation, but have never had issues before. How can I prevent this? What caused it?

Some ideas. A condom or a dab of a topical anesthetic on your glans may do the trick. Your physician can offer a very low dose of a selective serotonin reuptake inhibitor. Or you and your partner(s) can learn and practice the squeeze technique -- this is fun, will let you reprogram your nervous system to make you a superlatively excellent lover, and is your best long-term solution. Best wishes.