how to deal with a healthy relationship when all you've know is toxic ones ?

haii , i'm looking for advice on how to handle a new healthy relationship when the only relationships you've had in the past have been extremely toxic . for context , my ex who i broke up with in January and was with for a year was extremely toxic . he verbally and physically abused me , as well as cheated on me over 12 times (i stopped keeping track after the 12th time) . now you may be asking why i didn't break up with him sooner , and the answer is because he had me emotionally dependent on him as well as he would always manipulate me any time i tried to leave (tell me he would off himself if i left him) . anyways after finding out he had cheated again for the millionth time i finally had enough and i broke things off by just blocking him on everything without saying a word to him . he still to this day will make new accounts and harass me on multiple different platforms but i just ignore it and block the accounts . anyways , in April i started seeing this guy , i'll call him h . h was a super sweet and genuine guy from the very beginning , on our very first date he even asked permission before holding my hand . he treats me so well and has never intentionally upset me . my only problem is , i'm still so traumatised from my ex that my brain sabotages me sometimes and makes me think that h is only using me for some ulterior motive , or that he's waiting to get me vulnerable so he can take advantage of me . i know deep down that he would never do that but i still get those worries and they make things very hard . as of right now , we have broken up but we're still talking . i'm realising the decision was impulsive and it's not how i ACTUALLY feel about the situation , i only acted out of emotions . that's how i get , i make impulsive decisions out of reactions to intense emotions . like whenever i start feeling depressed my immediate reaction to consider suicide . he has witnessed this multiple times and has calmed me down and pulled me back to earth . like i said before , he's an amazing guy . i really don't want to ruin this because of my overthinking and impulsive decisions when i get scared . what should i do to better handle situations like this ?