The 24-year-old was given the elbow by Spence back in February, but the news only broke in recent weeks - and viewers saw the break-up on last night's show on E4.
And Louise told new! magazine: "I'm the happiest I’ve been in a long time. Normally when you mourn a relationship, you are pretty upset, but I'm the opposite.
"It's been such an emotional rollercoaster. I just feel really relieved and happy it's over. I'd been so depressed for the last four months of our relationship, I forgot what that was like.
"The day we broke up, I just suddenly found happiness again."
Viewers last night saw Spencer telling Louise: "It's f***ing hard to respect you when you allow me to cheat on you."
But Louise denied that, saying: "In no way have I ever allowed or condoned it! How does he even come out with comments like that?
"He obviously referred to me taking him back after he cheated and that is so appalling.
"He begged and begged for me back. I’ve obviously learned my lesson: never give people, well, fourth chances.
"I never should have got together with him. I feel like I wasted a whole year of my life on him."
And she claimed that the public was finally seeing the former star of The Bachelor for what he really is.
She said: "He started to play up to this villain character, basically just being an a**hole.
"I’d actually say the show reveals his true colours. This is him in all his glory!
"This whole series is what he's really like, which has been hidden pretty well before. It's a real shame because he's lost a lot of friends and respect from people."
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