An electrically disordered heart is undergoing a progression of the disorder. For some hearts it can mean several months, while for others it can take several long years for the progression to more difficult stages to manage. I don't know how long we're talking about for you, but it seems as if the bills are beginning to come due for you. You are moving along into a more advance stage.
Consult an electrophysiologist and do some serious research into catheter ablation. Unless you are willing to begin experimenting with anti-arrhythmic drugs, I do feel that you should get an ablation (if a qualified person, not me, knows it is likely to stave off further progression for a good long time).
I have had two ablations for AF. The failure rate for an index ablation to treat AF is a rather disappointing 25%, but much of that is due to both the early nature of catheter ablation, the uniqueness of each patient, and the skill and experience of the EP. Repeated ablations have a higher success rate. I don't know the stats for SVT, but I feel that they must be somewhat the same, maybe better. Again, more research for you, including finding the best EP out there near you who specializes in advanced stages of your disorder.