Been there OP! I really empathise as it can be such a minefield, although I've never experienced anything QUITE as terrifying as that guy who threatened to assault you (although I've heard similar horror stories from friends and the site's lackadaisical approach to it sadly doesn't surprise me either).
I've personally only ever used Bumble, I liked the aspect of women having to message first. I know it puts some people off but it made me feel a bit more confident in making the first move etc. I had a few one-off (or two-off!) hookups from it which were fine but attempts to find something more serious were a bit offputting... I'm only 28 but I really did begin to feel like I was never going to find someone for something serious because it was honestly like pulling teeth! I first wasted more time than I would like to admit to on someone who was simply chock-full of mixed signals and commitment issues and had no idea what he wanted from one day to the next, and then some time later went on a series of dates with a guy that were really nice, fun and varied and he seemed genuinely interested and attentive... and then with ZERO warning he ghosted me in the middle of a normal conversation and I never heard from him again.
That was the first time I'd ever been ghosted and it made me feel really bad (WHY do people do it!!!) and I was so fed up and ready to jack the whole thing in for a while or forever when I just happened to match with someone with whom conversations flowed easier than they had with anyone else, from the start we were talking A LOT every day and we arranged to meet up for a drink as soon as possible. After everything that had happened I didn't want to get my hopes up too much so I told myself it might end up being just a one-night stand/we wouldn't get on/he wouldn't message me again (yes I did sleep with him on the first date 
it just happened!) but we ended up staying up into the wee hours talking and laughing about anything and everything and he messaged me again as soon as I left his house the next morning (where he kissed me on the doorstep when my taxi arrived, swoon) continuing as we were, and some time after that we both admitted we had "caught feels". That was about 5 months ago and I'm still on cloud nine from his most recent visit on Thursday 
I have clicked with him in a way I don't think I ever have with anyone, including a guy I was with for over 6 years! He is fun, respectful, thoughtful, INCREDIBLE in bed, encourages us to communicate about things, we talk all the time when apart, he's told his family and friends about me and vice versa, we have used the L word once or twice etc etc etc. I certainly NEVER thought this would happen to me particularly after the random ghosting, I just assumed I must be terribly unlucky and it wasn't on the cards for me. Funny enough he had also only even matched with two people (me and one other girl before that who he didn't end up meeting) in the past 6 months or so and had ALSO been ready to chuck it in for a bit just before we matched, it almost seemed like fate woo but true!-
As @Fairycake2 says it really is just a numbers game and it does seem you have to weed through a lot of boring/insincere/strange people to find someone you really click with, which CAN be monotonous and soul-destroying and hard to remain hopeful throughout. I would say if you have only been using one site maybe try another, I have a few friends who are on several at the same time but it seemed too overwhelming to me And if it is starting to get you down then by all means take a break. Dating is supposed to be fun (even though it's fundamentally very stressful!) and if it's causing you more harm than good then it might be worth taking a step back so you can come back to it more refreshed when you're ready. I wish you the best of luck 